Callum Au on Sing Seven Seas

Celebrated for his intricate and elegant big band arrangements, Callum Au has quietly become one of the most in-demand musical voices for those on the UK jazz scene. Having worked with artists including Michael Bublé, RAYE and Josh Groban, Au’s work blends classic swing traditions with a modern cinematic sensibility, balancing technical sophistication with warmth, energy and melodic flair.

Now, with the release of his latest album Sing Seven Seas, Au steps into the spotlight as both arranger and trombonist, in a project expanded ensemble of more than eighty musicians. Rich with orchestral colour, sweeping arrangements and standout solo performances, the record marks a bold new chapter for the composer and trombonist. Speaking about the album, Au reflected on the process behind such large-scale work, the inspirations that shaped its sound, and the thoughts behind separating the tracks into two volumes…

Sing Seven Seas is a major project. At what point did you realise it was going to be on such a large scale, with over eighty musicians involved?

The project incorporates all of the things that I really love in music, and what I like the most is large ensemble music in all sorts of shapes and sizes. I find that both the jazz orchestra and the symphony orchestra are my favourite mediums for live and recorded music. If I'm going to be writing music that's from my perspective, that's always where I'm going to go.

I do a lot of work as a sideman, or writing mostly orchestral arrangements for people, but this is the first project where it’s more focussed on me. The orchestra and big band sound is a natural follow on from that.

You’ve worked with global artists like Michael Bublé, RAYE and Josh Groban. How does leading your own project compare to arranging for others?

The way I think about it, my job as an arranger is to make the artist feel as comfortable and as happy as possible with what's going on around them in the orchestra. In this case the job's the same, except I’m the person who has to feel comfortable in that way. 

It all kind of links together, really. I find that one directly enables the other. Purely from a practical standpoint, I wouldn't have the funds to do something like this without the commercial work, but secondarily, all the musicians who I work with all the time in the studios and in concerts are ones that I've met through doing work like that. The players on this record are people like Andy Wood and Karen Jones, who are absolute tip-top, and first call orchestral principals for the film sessions. I did an album for Josh Groban, about three or four tracks, and when I turned up it was all the same people for that project that are also on this one – they directly link into one another like that.

Do you find that having quite a unique knowledge of the players involved influenced the way that you scored the music?

Absolutely. I think the most people playing at once is about sixty-five, not all eighty are playing at the same time. I had three different brass sections or sax sections over the course of the week that we recorded it in, and I specifically picked the repertoire for each day based on how I thought people would play – not just as soloists but also as ensemble musicians who you can rely on to play in a certain way.

I know how the second tenor player is going to play, or how the third trombone is going to play. I know who to pick for that job, and that's what I've done here. It was all done in a very deliberate way. 

What prompted the decision to release this album in two volumes versus releasing it as a single body of work?

Well, it's separated into two halves – both thematically and practically. In the practical sense, it’s to do with how music is consumed today. People don't really listen to albums anymore. They listen to single tracks and then they move on to the next – because of the way streaming is set up, it's not really designed for a great lump of music in one go. A lot of people just have things set to shuffle; they'll put one thing on and then they'll be guided onto something else. So the consideration is that by releasing volume one on streaming, maybe nine to twelve months ahead of volume two, there's a hope that some people might buy the physical album or the digital downloads so that they can get it early. 

I think it's nice to have some sort of connection like that. Thematically, volume one is just me doing basically exactly what I want to do. It's quite scattershot in a way – there's loads of different styles and influences. There's everything in there from classic big band stuff, classical music, some prog rock, and even some minimalist stuff. The second half looks at big band music more from the lens of what's come before.

‘Bandwagon Blues’, the opening track, deliberately quotes tons of famous big bands – and we're all literally jumping on the bandwagon. The four pieces in the middle, slightly tongue-in-cheek, is ‘The Influences Suite’. Each one's dedicated to four of my greatest influences. So that's Duke Ellington, Count Basie, Dizzy Gillespie/Maynard Ferguson (it's kind of half and half), and Kenny Wheeler.

If anything, the first half is not quite breaking the tradition, but it's building on the tradition, whereas the second half is respecting it. I feel like the jazz orchestra and big band tradition is something that we in this country do very well; we've got a very long and great history of it. So it feels like I should acknowledge that.

Did you find that when you're drawing on these hugely influential figures in that genre, was that tricky or did you find that you could access that quite easily?

I mean, to an extent, that's kind of what my day job is. For example, for the Michael Bublé album that I worked on during lockdown they asked me to do a ballad called ‘Don't Take Your Love From Me’. I was on the phone with Michael and his musical director, and they were quite clear in that they said ‘We just hear this as a lost Nat King Cole track. It’s a song that we could have discovered in the MGM lot that Nat King Cole never got around to recording.’ 

What that says to me is that there's a specific way that you do that. You get to understand it, or it comes a lot from listening to a lot of the arrangers like Gordon Jenkins or Nelson Riddle. The task is often set to me with a specific intention in terms of the sound – whether that's a 50s Riddle era, Rodgers and Hammerstein sound, or a disco orchestra from the 70s. Because of what I do routinely, I've got to have all those tools at my fingertips, and it's how I interfaced with writing music from the start. 

You've also got to have the right people in the right seats to make the sound, and especially the section leaders. They're the most important people because everyone else can follow them, but it’s the section leaders that set the whole tone.

It fascinates me really, how an orchestra is both hierarchical and not hierarchical at the same time. Everyone has these individual roles that may or may not relate to another role. You have a sense of a chain of command and the idea of following the leaders, but you have to know when not to follow them as well. It’s ever shifting. 

‘Swipe Right!’ captures the energy of social media culture, but how do you translate something as fast-moving and visual as that into music?

Everything about it is a bit ADHD. There's about twenty-five seconds of ridiculously fast, ridiculously impressive piano, then twenty-five seconds of the same in the trumpets, trombones, and saxophones. The clarinet solo by Duncan Hemstock, the Australian clarinetist, is just out of this world. He plays twenty-one bars without breathing.

The point of it is that it's frenetic and everything is dialed up to the most attention-grabbing, most hard to look away from music that I could think of. At the same time, stylistically, you might think it's old fashioned – it's basically swinging jazz music like they would have played in the 40s – but that’s the last time really that big band music was super popular. It was the mainstream thing, popular enough that people would engage with it, so that’s why I wrote that track in the way that I did.

AI is causing a lot of conversation in the music industry at present – did you use this as a tool in your composition ‘jazz.ai’?

Not at all. There's no AI used in any of the production. The writer of the composition’s story is Katie Emmerton, who's married to my guitarist, Tommy. I gave her the outline and she wrote the script. It's more of a commentary on what the AI stuff is doing – that track, I suppose, has got a serious message, but it's lighthearted at the same time. 

I don't want to be all doom and gloom because I think there's tons of positive things that can come out of it. It's going to create so much extra time for people, for example. There's jobs that nobody will ever have to do again, that nobody particularly wanted to do in the first place, because this technology exists, and it frees people up to do all sorts of amazing things if they want to. At the same time, obviously the tail risks are huge in a technology like that. There are things that could go seriously, seriously wrong, and it's not just music all starting to sound the same. That's the least of our concerns really. So that's where it came about.

There are some quite emotionally significant links or influences to some of the pieces that involve your family – could you give some insight into that?

The first one is actually the one we just talked about, ‘jazz.ai’, which I wrote because of my kids who were watching the Disney ‘Sorcerer's Apprentice’ over and over again. It was just on repeatedly around the house. And I began to reflect on the idea that this is going to be being listened to a lot and I better have something on it that they're going to enjoy. They're now four and two. I'll consider it a partial success because one of them hates it and the other one asks for it all the time! They call it the ‘saxophone story tape’, so that's what it's called in their mind. 

There's a tune on the second volume called ‘Through the Deep Dark Woods’, where the melody at the front of the tune is something that my then three-year-old was singing around the house. It’s an absolute earworm. It gets stuck in your head, though he's forgotten all about it now that it's a year later. He can't actually remember doing it, but it was six months at the top of his voice all around the house singing this little tune, and I just thought ‘Okay I've got to do something with that, then’. So that’s the origin of it all, and I use the main melody at the beginning.

And ‘Stardust’ is dedicated to your grandparents…

Yes, well very sadly we lost my Gran in the week that we had these sessions. My Grandad is still alive and he's ninety this year, and she was just a little bit younger. She loved that old style music, and she would go around the house and sing all the time. She used to sing all those old Jerome Kern, Oscar Hammerstein musical theatre songs, and I remember her singing ‘Stardust’. It’s one of the only two full tracks on the full record that have the string section on it, which is the reason that's not on the streaming release, because I wanted to give a bonus track for the physical release and it doesn't quite fit quite as neatly with all the others. 

It's a whole album of things written by me, except for this one really old 1920s standard, so it doesn't quite fit, but it seems appropriate as a bonus track. I realised we had a bit of time left over at the end of the string session. So the night before the session, I wrote that arrangement. And then it took me about maybe a couple of hours and then we recorded it in the very last part of the session. 

Touching on what you mentioned earlier, in terms of considering yourself as the artist but also as the arranger, did you find that you balanced those fairly easily?

Well, I certainly took longer over these. I mean, once I have the material I can write it and orchestrate it fairly quickly because, again, that's my job. Coming up with the material itself, that took a long time for some of them. Some of them were a really long time in creation and I had to commit to spending a decent amount of time writing.

Can you tell me the inspiration behind the album artwork? 

Well, the cover is a bunch of fish jumping out the sea and that is because my title for this album was originally ‘Big Fish’. The reason for that is that everyone is an orchestral principle or a  jazz soloist in their own right. Everyone's playing at a really high level so it was like here are all these big fish swimming in the same direction, working together. But then I realised that ‘fish’ is the same plural and singular, so it might have sounded incredibly arrogant if people didn't have the backstory, but I'd already commissioned the artwork with the title at the time. So I came up with a different title. 

In essence though, the inspiration came from the people involved – everyone here is utterly extraordinary. I'm an instrumentalist myself and play all sorts of things, but I guess I feel that the thing that I'm really good at is more on the writing side. 

There's people involved like Emma Rawicz who’s phenomenal, and Jay Craig, who is an elder statesman of British jazz at this point. He was the baritone sax player with Buddy Rich's band back in the day, and if you want that kind of big, fat, beefy, low end baritone sound, no one does it better. We had Karen Jones, who played the flute solo on Harry Potter and the Prisoner of Azkaban, and Mark Nightingale, who is probably Britain's most famous trombone player and has always been a personal hero of mine. 

Jake Wilson is a ridiculous prog rock guitar player who I have known for a long time, but I never get to work with him as a musician very often because we're in such different worlds. It was amazing to get him involved because he's one of the best musicians I've ever met. It's a bit like one of those soap opera episodes where they get the cast of Frasier, Friends, and The Simpsons altogether on the screen at the same time. 

How do you imagine this kind of project translating in a live setting, especially for your album launch at King’s Place?

So we're basically playing one volume per half. Half one will be volume one, half two will be volume two. I don't have strings, unfortunately – it's basically down to the stage size and we can't get them in. I've scored everything for five trumpets, four trombones and me. I'm doing all sorts of trombones and keyboards and things, the piano, bass, drums, guitar, rhythm section. I've made everything to a greater or lesser extent work with that combination. 

Do you see Sing Seven Seas as the start of a new chapter for you going forward creatively or do you have something else that you'd like to pursue?

You know, I haven't really thought about what's coming next. I'll get it out first. I mean, I love composing and the process of basically arranging for myself is enormous fun. I'm much better known as an arranger and I hope I'll always be busy as an arranger, just as long as AI doesn't come and ruin that. It would be lovely to do loads more stuff like this, and I guess up until now, I didn't really feel like the composition was up to scratch. It wasn't at the same standard, and when you're working to a certain standard in one sphere, you don’t want to do anything that you don’t feel is ready. But I guess it's ready to come out of the oven now, so that's a really good thing.

Physical formats of Sing Seven Seas is available from 12th June 2026, and Volume 1 is available digitally from 5th June 2026.