Writing a book can be a kind of bliss, surrendering to the slipstream of the “flow” experience, letting your imagination run free. Then you need to grind the cogs of your brain into a different gear to tackle the editing, and yet again when bringing the book out into the world.

Some aspects of the latter process are more enjoyable than others. As a “high-functioning introvert” I’ve never fully made my peace with social media, especially when it comes to self-promotion, but it’s a modern necessity and can be fulfilling when you manage to really engage with readers, reviewers and other writers – or when you find your “tribe” online. It also focuses the mind and asks you to think creatively when communicating about your work.

One of the most enjoyable recent exercises for me was becoming a “DJ” for my books and compiling the ultimate Children of Sarah playlist. The process of exploring songs to complement a particular character, theme, setting or storyline was remarkably satisfying – even enlightening at times. It was wonderful to spend time with a few old favourites while also discovering some new music, or at least different versions of familiar tunes.

Some choices were obvious, even appearing in the books as something a character is listening to or dancing to or thinking about. Or which makes one character remember another…. music is so deeply connected to memory, isn’t it? Other songs were easier to match to certain characters (Eloise and Eloise – she even tells KC which version she prefers in Bone Lines) while some choices were more about a recurrent motif, an event or a location.

And, of course, I had to actually like the music, too. It had to be something I would enjoy listening to (and I have done since, many times, to the annoyance of my neighbours!) as much as I hoped others would. Even if it’s an oddly eclectic list with a few “interesting” shifts between musical styles!

I tested the playlist on a couple of people before I finalised it, and someone suggested Metallica’s Trapped Under the Ice, but I’m afraid my days of headbanging are long gone. Indeed anything really heavy or jangly or thrashingly loud – of any genre – can be physically painful due to my tinnitus.

So the choice was not so much influenced by relevance of title or lyrics, but about how suitable it felt in terms of resonance, emotion and tone. Having said that, in many cases the lyrics of some songs discovered by happenstance often turned out to harmonise perfectly with a particular theme.

There’s one artist who appears three times, my lifelong musical love, David Bowie. He also happens to be the favourite artist of Max, the astrophysicist in The Fire In Their Eyes, although Max being much younger than I, this passion is perhaps more about retro-cool? Then again, I can easily imagine classics such as Space Oddity and Life On Mars awakening his fascination for astronomy as a boy.

So what about the music that didn’t make the cut? Perhaps Holtz’ The Planets really ought to be included for the star-gazers in the books, but while I loved these compositions as a child, when I listened again it just didn’t feel right for this particular playlist. I’m still not sure why, but I suppose our tastes fluctuate with time?

I knew I wanted Hallelujah on the list, its unforgettable chorus connects both John and Callum. I listened to various versions, many of which I loved, including Jeff Buckley’s, before I came back to the original, feeling the gravitas in the voice of Leonard Cohen was a better fit.