The record incorporates a cast of guest singers from across (and beyond) the Bella Union-family including Marissa Nadler, former Midlake frontman Tim Smith, Cameron Neal (Horse Thief) as well as Liela Moss of The Duke Spirit, Ghostpoet, and Sharon Van Etten.

Below, Simon takes us through the tracks on Ojalá and explains how each song and vocal collaboration came about.

"Score The Sky" feat Liela Moss

This was the final song I wrote for the record. I had just returned from America playing a film score live at the San Francisco film festival with Mercury Rev and had purchased an instrument called a Mellotron for the show.

When I got back home, I had fallen in love with it and wrote all the music late one night at the studio. I stayed up all night adding intricate guitars and layers of horns, bass clarinets and flutes and it felt amazing. I felt it completed the album perfectly and I came into the studio a week later but all the files had gone missing! I spent about three months trying to work out what had gone wrong, checked on every hard drive I ever owned, checked on my home computer in case I done something stupid, asked friends if they'd borrowed a hard drive, knowing they hadn't and it really felt like an episode of Columbo.

I eventually had to except that all the music had gone. I hadn't backed it up foolishly but I had sent a rough mix on MP3 late that night to the singer Liela Moss so I at least had a reference of what I had done. It was kind of heartbreaking and it took me awhile to summon up the energy and brain power to re-record something i improvised because I know from experience that re-doing something is tricky, it never has the same energy and tone as it did the first time you wrote it. Liela had already completed all her vocals so at least I was able to play off those and I am really happy with the final result even though it may not be exactly the same!

"Reckless" feat Ghostpoet

The original two four-day improvised sessions were of me playing either piano or guitar and Richie drumming/playing sax. This was on day two of the first session and came together in just a few minutes. It had a dark but soulful groove to it, almost trip-hop in a way though this was not contrived. The great thing about writing in this way is that while of course, as musicians - like it or not - you are always subconsciously taking on board influences from elsewhere, it is very TRUE and revealing and comes close to finding the essence of your sound.

You also have to remember that Richie and I had not really been in a studio making our OWN music for almost 20 years, with this sense of freedom and clarity, and the EXCITEMENT at just ‘being there’ was palpable and also needs to be stated to give some context to these sessions! As we finished that first take of it, all I could hear in my ‘head’ was ‘GHOSTPOET GHOSTPOET, you HAVE to get GHOSTPOET to sing on this’.

As soon as i’d got a rough mix of the track, I sent it to Obar and immediately he loved it and recorded a basic home demo to send me. He nailed it. He genuinely loved the darkness of the music and the groove, and reacted to it in the spirit the music was conceived too. A few weeks later he went to my studio in London with our engineer Iggy and recorded the vocals properly and what he did that morning is what you hear on the record.

"The Tide" feat Phil McDonnell

Also another tune that came out of the first session in Hackney Road, but that probably didn’t really come to life until much later. I’d recently moved down to Brighton and brought all the improvised drum-piano tracks home to my spartan recording set up in the living room. It was basically Ableton, a recording programme on my computer, a guitar and a new Eventide pedal and i added all the guitar parts to the backing track late one night but for the life of me I could not get a bass line to work to my satisfaction.

I had recently befriended a band called GULF who i was interested to sign to Bella Union and i asked the bassist if he fancied playing it. Mark the main songwriter of the band heard about it and called me to say that the bass lines in GULF were all him so would I like him to do it instead? I wasn’t hugely bothered, I just knew I wasn’t coming up with anything I liked and had little confidence anyone would be able to if I'm honest!

Somehow, he summoned one of the coolest baselines on the record out of nowhere and immediately the song was elevated and moved so well from part to part. It is such a melodic bass part and i am so glad he called me to intervene! The vocals are done by a singer of another band i was championing via my radio show I was doing at the time. They were called Night Engine and had a couple of huge tunes. I loved the theatricality of Phil’s vocals and adoring voices like Billy Mackenzie’s growing up, this vocal hit the spot for me.

In explaining what I wanted, I left it very open and tried to give each vocalist the confidence to let go and embrace the spirit of the sessions that the music had come out of. The ‘demo’ version of the vocal, ie. Phil’s first takes were so good and full of energy and originality that i ended up using them for the finished track. Because they were recorded quickly at home with acrappy mic, the intention was to go into the Shoreditch studio with Iggy and record them properly but good as those sessions were, I never felt they captured the vibe as well as that first take demo version Phil did, so I used that in the end.

Thanks to my mixer Paul Gregory who somehow made the vocal ‘sound’ as good as this, because there were certainly imperfections but I love mistakes and rough edges in music so this was never a problem for me.

"The Places We’ve Been feat Karen Peris'

The beauty of this kind of project is that for each piece of music, my imagination could run wild with who would be the right voice to glide over the top. Doing what I do for my ‘day job’ makes this kind of curation fairly easy for me. I knew immediately who would be the right voice for each piece. And I am no shrinking violet, i’ll just get online, find a contact email or phone number and write them/call them etc. Nothing to lose right?

Karen Peris has for almost 25 years been one of my favourite singers. The album Birds of My Neighbourhood by her band Innocence Mission has been in my top five records of all time for as long as I can remember. You know how some voices just hit you in the heart, the groin or the head? Hers kills me, I find it very emotional and it goes straight to that part of me. There is an inherent sadness to it and after writing the music for "The Places We’ve Been", I knew i had to ask her.

In all this time, she has never sung on anyone else’s music so i knew it might not be straightforward but i found her and her husband Don, who together are Innocence Mission, on Messenger on Facebook and sent them a couple of messages! Incredibly they replied positively and asked to hear the track. As I sent it across i felt like a teenager asking a girl he had had a crush on for a date! Silly really, because Karen replied quickly to say she loved the track and would be delighted to try and write some vocals for it. I cried like a baby when i got her performance through on email. I think i listened to it 20 times straight, barely able to deal with the fact that this had just happened!

"Frenzy, Fear" feat Hilang Child / "Stampede" featuring Hazel Wilde

These two pieces came together very late in the day and started out - in my mind anyway - as something quite different to what they ended up as. I felt it would be cool to have a bonus disc of ambient music so I asked Richie if he minded if i went it to the studio alone and just messed about on piano and guitar with some improvised noodlings!

So I went to this amazing place along the coast where Nick Cave and Warren Ellis record their Bad Seeds stuff and their soundtrack work, and it has an incredible grand piano in there that basically you just sit at and the tunes just appear. It has a magical quality to it, and while I only had two short days in the studio i came up with about seven other tracks for the record! It’s all about that piano.

I’d been a fan of Ed Riman (Hilang Child) for a while and sent him one of the pieces. He said he’d love to try something and went over to Shoreditch with Iggy. He recently told me he’d been listening to a lot of Brian Wilson and thinks the influence came through! I kinda know what he means in terms of the harmonising but this stopped me in my tracks when i first head it. The space in the piano parts was the perfect backdrop for this incredible performance from Ed. Immediately i knew this was no bonus disc of noodlings! This was going straight on the album. "Stampede" was again from the same session, very strange piece, long notes, no discernible tempo or structure and sending it to Lanterns On The Lake' singer Hazel Wilde, I knew what would come back would be special and you’ll know how much we loved it, because it closes the album.

"Asphyxia" and "Give Your Heart Away" feat Gemma Dunleavy

I heard Gemma sing with the band UNKNWN who put out a couple of great tracks in 2014 and by the time i’d started working with her on these tracks, the band was no more. The tracks Richie and I wrote were melancholy and dark, and she elevated them with her bruised and sensitive writing.

These were both from the first four-day sessions in Hackney Road. I had suffered with some emotional and physical dramas over the last 20 years and Gemma knew how to tap into that energy and she really hits the nerve with both these tracks. The guitar solo in the middle of "Asphyxia" is by Jemma Freeman from the band Landscapes and is also a highlight of this track.

"She Led Me Away" feat Tim Smith

For those Midlake fans reading this, it will have been a surprise to see Tim guesting on a track. Notoriously reclusive and shy, the archetypal perfectionist, Tim is often unable to finish tracks because his own standards are so, implausibly at times, high. So it was with only vague hope that I sent the music for this song over to him.

I wondered, for a fantasy moment, if maybe an enjoyable experience with this, might have a catalyst affect on his own music, and it was therefore quite thrilling when he responded positively and swiftly. Having known Tim for 13 years, this initial enthusiasm alone didn’t wholly convince me but lo and behold within a few short weeks, Tim wrote to say he had something, "although it probably isn’t any good and not to worry if you don’t like it etc" (Typical Tim there, straight on the defensive!)

Of course, i knew at this point, it would be great and yes when he sent the demo over, it was. In fact the "demo" was perfect and needed no tidying up or re-recording. When Paul mixed it, Tim remarked that the "lead vocal" had been balanced beneath the harmony vocal and was I sure it sounded right, and I tried it the other way but to be honest maybe this beautiful natural accident indeed gives the vocal that unique feel that captures the melancholy mood of the music.

It started off with piano and drums and bass, but stripping it back to basically just acoustic guitar and vocals was something I felt worked best for this song. Tim hasn’t sung on another track outside Midlake since The Chemical Brothers' "The Pills Won’t Work" so when he agrees to sing on your song, you don’t want to hide it away beneath tons of music, so the sparse approach worked really well in this moment.

"The Engine" feat Hilang Child

A lot of people’s favourite track, and certainly the longest on the album, it was one of the first tracks we jammed on the second day of our first session. I had done a few piano based tracks and thought I’d switch to guitar just for a change (I’m not a guitarist really so I often use open tunings to get me started) and plugged my Fender Jaguar into a couple of pedals and within a few seconds just had this huge sound. It was like Kevin Shields had walked into the studio and immediately Richie was loving the vibe and started drumming along.

We recorded eight minutes of this piece and a few days later when I took it home, I immediately added the bass and a few guitar overdubs, more as emphasis than any other parts, as it was already quite "full" up despite only having one guitar, bass and drums on it - something I was trying to incorporate more with these recordings was not to over-elaborate.

The vocals were the complete opposite in terms of speed of coming together. It was almost a year before I sent this one to Ed Riman. I knew i wanted a male voice, but I didn’t get the picture in my mind until later who should sing it, but once I decided it needed to be Ed, and after he heard it and agreed, it came together in a day or so!

The lyrics were inspired to a degree by Gulliver’s Travels and with its satirical take on both the state of European governments and petty differences between religions - this just seemed so appropriate given today’s political and social malaise, and we really embraced this element Ed brought to the song.

"Life Inside A Paradox" feat Cameron Neal

The first track by Lost Horizons to appear publicly, again it came from the first session and stands out as probably the one upbeat moment on the album! Cameron is an amazing songwriter - especially for such a young man, and I love his band Horse Thief - and I knew this track would be perfect for him.

He took no time at all in working on it as soon as I sent it to him and the whole thing was finished really quickly after Sharon Van Etten added her delicious vocal harmonies to Cameron’s lead. The vocals and lyrics are unique and unusual, and I was in love with it immediately he mailed it to me! I was working with Mercury Rev at the time on their new LP The Light In You and they heard about my new band and suggested we do a split 7” single, with one of their tracks and one of my Lost Horizons tracks. I loved the idea but i wasn’t really ready. So i got this one finished as quick as I could and sent to Paul to mix for the 7”. It sold out of two pressings so it was a really cool thing to be part of.

We did remix it for the album version, because as the earlier version was the very first thing mixed, by the time we’d done the rest of the album, the sound and sonics of the rest had moved on a bit, and I am glad we did this because the 7” version is a little rough around the edges.

"Bones" feat Bethany Cannon

As all our music is 100% improvised it’s not that easy to talk about each track so specifically because I literally just react to my mood and the circumstance and working with a drummer like Richie, I am always trying to think about playing something that works for both of us. We didn’t have much of a budget and had to use v small studio spaces, or my room under the cafe in Brighton, so sometimes things are how they are because of environment.

With only two of us, I would often start with a piano because it’s a good instrument to write on and jam on, for me anyway. This piece was recorded in our second of the two four-day sessions and i was feeling like I wanted to hear a kinda gospel/soul mood in the music and had that in the back of my mind as we were jamming this. It developed that way once I brought the track back to my home studio, and then adding the gospel choir, not in an obvious cheesy way, but just as a flavour, took the track to where it needed to go. Beth’s vocals are incredible and so powerful and such a counter to the soft laid-back vocals of the gospel singers.

"Amber Sky" feat Soffie Viemose

I started this piece on a Rhodes piano and was immediately in love with it. Adding the bass and guitars back at home, it felt like the track that summed up both Richie and I perfectly. It has the melodic, dub-feel on the bass that I guess is a sort of default setting for me, and Richie’s fluid drumming style.

Soffie’s vocals made me cry when I heard them for the first time. I knew she would get it, and it’s one of my favourite performances on the record. It just feels like the closest I have come to writing a piece of music that i could never tire of.

"Winter’s Approaching"/"I Saw The Days Go" By feat Marissa Nadler

All the tracks with Marissa came about quite unusually. I thought I was finished with the Lost Horizons album once we got to about ten tracks, but I had the urge to go and record on my own at this lovely studio near my house which Warren Ellis had recommended to me, with a mint grand piano.

I had two short days there and got a ton of recordings done, no idea really what I had, as it was such a blast and I need time to reassess these improvs. When I listened back, I realised this was the missing part of the album, and I set about arranging them a little and adding sparse backing before then thinking of the right voices.

I’d wanted to use Marissa Nadler’s voice on the record but nothing had seemed quite appropriate till now. We have a lovely connection and it’s always very easy for me to relate to her, socially and musically and it seemed like me sending these piano noodlings was very timely for her too, so one song turned into two, then into three then four! I didn’t want the LP to be Marissa-dominant even though I loved all four pieces, so I used them across the bonus disc and the LP and that worked perfectly. She wrote and sang her parts in just a day or two and i think we were both just very inspired at the right time for each other.

Ojalá is released on 3 November via Bella Union