Few artists have the right to moan about struggling to finish an album the way Jason Pierce does. In 2008, he released Songs in A&E, an album completed while he was recovering from a life-threatening bout of Periorbital cellulitis with bilateral pneumonia. If that wasn't enough, he was diagnosed with degenerative liver disease during the making of Spiritualized's seventh studio album, Sweet Heart Sweet Light (originally titled Huh?), for which he had to undergo chemotherapy and take experimental drugs. However, instead of channelling all of the frustration he must have felt, Spaceman chose to look on the brighter side and make the most inspiring music of his life. In many ways, Sweet Heart is the most complete Spiritualized album yet. You could say for his latest masterpiece, Pierce had to take life-saving drugs to make music to take drugs to.

Sweet Heart Sweet Light is you embracing the pop song. Is that something you've avoided in the past?
Yes, like properly tried to avoid it; it's the bit of Spiritualized I'm the least comfortable with. I like the abstraction and the distortion. I like the stuff that veers left field, but the sort of straight ahead pop stuff is where I feel awkward. I figured this time I would embrace that and go for it, and I wouldn't hide behind anything. Only because I haven't done that before, it seemed like the least comfortable way to go and I figured it would leave me exposed. You can hide behind distortion and the abstract sound, and this way it would be, like, an Emperor's New Clothes kind of thing. With pop music, I just felt I couldn't do that; I've never made a record like this before. And even though Spiritualized probably aren't as left field, as I see it, I always think of it as less pure and quite abstract. I mean, if you listen to it on record, it's probably not as abstract as I always think it is. And this time, I thought, "I'm going do it" and that was the starting point. But I don't think I've made one; I don't know if I've made a pop record.

You've said in the past that you sing into a Dictaphone, put the music to piano and then have someone else arrange the strings. Has that changed?
You mean, have I learned to write music [laughs]? No, I'm still doing the same thing. I realized making this record that I like to invert the chord – take the bottom note and put it higher up. I just keep doing that. When you invert a chord in gospel music, it's the thing that makes it seem like it's getting higher. Whatever we put down, I find other stuff to put in as well.

Music making is often a long process for you. Was this one any longer considering what you were going through?
Yes, it seemed like it was going to take forever. And another reason why I decided to try and make a pop record was that I thought it might be a little easier. But as anyone who's tried to write pop songs knows, that's not going happen. I was a little bit naive there thinking it would be easier. Somewhere in the back of my head I was thinking about all of those great records that have never been finished, like Brian Wilson's lost record. And in an odd way, that made me want to finish it because I figured it was a lot easier to make an unfinished record than it was to finish a record. That kind of kept me going, I guess.

Your liver disease was relatively unknown until just a couple weeks ago, despite your treatment happening a while back. Were you hesitant to reveal that to the public?
I guess it didn't come up – nobody really asked. Also, I didn't want to say anything unless… I now know that I'm cured and I didn't want to say anything without knowing. I didn't tell anyone while I was being treated because I didn't want people asking after my condition all the time or treat me differently because of that.

Have you found that there's more interest in your medical condition than the music?
It seems like that's the story now and that's not a good thing; it was never meant to be the story.

I was thinking about the lyrics to "Medication," from Pure Phase: "Every day I wake up/And I take my medication/And I spend the rest of the day/Waiting for it to wear off…"
The irony wasn't lost on me. I was taking these drugs that – actually, they were doing me a hell of a lot of good, but the side effects were pretty poor. But I didn't listen to "Medication" during the treatment so I didn't see the connection. I do now.

Did playing Ladies and Gentleman in its entirety live spark any kind of inspiration for this album?
Yes, they were amazing shows; they were something else. In a way, it wasn't negative, but they put a kind of fear in me that I didn't want to be a part of that huge trend that's around now, to look backwards. Like, "Rock'n'roll is about looking back; it was great ten years ago. This is a classic." That kind of thing. I wanted to make a new classic record. And I don't want to say that it's a classic record in any form; I can't say that, but it was more that little voice telling me, "Don't get sucked into this." It's a beautiful thing to play, but it's so important to keep pushing forward; it's important for being an artist. I love music too much; I love rock'n'roll and everything about it. There is an awful lot of melancholy in the writing of this record, partly to do with music, but partly to do with everything that is alive and resigned to history. Doing those shows was kind of a wake up to not fall into that. As beautiful as the shows were, I felt like I was in the catering industry. "Here's the show that you've been listening to for the last 15 years."

Festivals like Coachella like to offer big money for reunions and doing something like playing classic albums.
It's easy to do. There's money, but we spent all of the money on the shows. A 50-piece orchestra! There's money in it, the promoters hike the ticket prices, so on all of those shows you pay more because it's your favourite band playing your favourite record. And that was the shock as well: suddenly this world opens up where you can make money and do well for yourself, but in a way that was more shocking. It's so easy to fall into it, but it's more important that you don't. No, actually, it's only important that I don't. I'm not judging what anybody else does with there life, it's just important that I didn't do that with my life.

Did you ever get offers to reform Spacemen 3?
Yeah, kind of, but you know, you make these things as well. People don't always come out and ask, "Will you do this?" It's almost like people think you sit around and wait for these mysterious figures to suggest something. The bands have to engineer it as well; you have to actively look to do these things a bit.

What's the thinking behind the album cover [the word "Huh?" inside of an octagon]?
It was there through the record; it was always the title of the record, in a weird way. I'm just looking at it now. It was the mental state I was in while I was making the record. Like everybody had been bemoaning the lack of twelve-inch record sleeves and I didn't want to do that anymore. I wanted something that would work, like – in a strange way it was almost like a medical symbol, the periodic table. It works in any way: the CD, the tiny little square on your iTunes and the record. Like I said, it was the title and I think if I put it as the sleeve the record would be known for that, regardless of the fact that it was called Sweet Heart Sweet Light.

What made you change the title?
I couldn't imagine people buying it; I couldn't imagine people asking for it. I had this kind of Monty Python-like thought about people buying this record with that name. Y'know, going, "Huh?" and then repeating themselves; it just felt too weird. Now that it's out, it seems almost normal, like it wouldn't have been such a big deal. At the time I was putting it together, I didn't see that happening.

Was there any talk about doing special packaging for this album?
There is no special edition because the editions we did before weren't meant to be special editions. There are 50,000 pill cases for Ladies and Gentlemen; there were loads of glow in the dark cases for Pure Phase. The idea was to make that the edition. Putting this together, it seemed as though everyone's doing special editions. Like, "What's the edition? What are we going to add to the box? What can we give away with this?" And it just seems like junk, so I just stayed away from that. The record is going to be in a white box, as good a quality as we can make with every one like that, right across the board. I can't say it's like the Pure Phase box, but that is the edition. After the first pressing, it's not going to come in a cheaper case. That is how it's going to be.

Your daughter, Poppy, sings on "So Long You Pretty Thing." Why did you want her to sing it?
A lot of the record was about time passing, not just music, because everything slips away and becomes part of history. And she wrote those words at the start of "So Long You Pretty Thing." I could have asked her to let me have the words, but it seemed like such a special moment. I've listened to this record lots; I've been making it for years. It kind of wears you out making a record and it has reached a stage where I can barely listen to it, to be honest; it reminds me of a very bad year. But that little moment with her singing, it still affects me the same way it did when it was first recorded.

When did you first hear it?
I just picked her up from school and she was singing it on the way home; it was the tune that I liked more than the words. "If you feel lonely and the world's against you" doesn't seem like a big deal, but I always liked how "and the world's against you" is always one syllable too long for the line. That's a childish thing; it's not something you can fake. As you get older, you choose your words more carefully; you learn the craft of how to put your words together. I think those words are special because they're not like that.

Is she excited about having her song on the record?
Not so much now. Time goes by so fast for kids; it's been two years since she did that. That's one-fifth of her life. So, for her, it's like her old voice. I don't think she feels she's that person anymore.

She must be looking forward to a nice royalty cheque though.
[Laughs] Probably. I think she will be.

Does she see this as a chance to launch a music career?
It wasn't about that. I'm not trying to launch her career, though I think she would eventually like to do that. It seems like a good idea, especially when you're a kid because there's a lot of doing nothing when you're in a band.

Read a review of Sweet Heart Sweet Light here.