I've been composing music for a children's sleep app for over two years now. Before that I scored 6,000 television episodes and award-winning films. The rules are completely different.
Television music is designed to keep you watching. Sleep music is designed to help you stop. That sounds simple. It isn't.
Here's what I've learned about what actually works — and what doesn't.
The Science Part
Start with tempo. Music between 60 and 80 BPM naturally synchronises with a resting heart rate. The nervous system responds to that match and begins to slow down. This isn't subtle — it's measurable. If your app's music is above 90 BPM, it's tricky, you're working against the biology, but not impossible.
Then there's instrumentation. Acoustic guitar, piano, soft strings, and ambient textures create warmth without stimulation. Anything with a strong attack — drums, brass, sharp percussion — activates alertness. For children specifically, the timbres that work are those that resemble the human voice in some way: warm, rounded, slightly imperfect.
Dynamics matter more than most people realise. Music that stays at the same volume and energy level becomes wallpaper — the brain tunes it out. Music that moves gently downward in energy across its runtime — gradually quieter, gradually sparser — actively guides the listener toward sleep. The arc matters as much as the notes.
The Part Nobody Talks About
All of that is the technical foundation. But the thing that actually determines whether music works for a sleep app is harder to quantify.
It has to feel safe.
Parents choosing music for their children are making a trust decision. They're putting their child to sleep with a stranger's composition playing in the room. The music has to feel like it was made by someone who cares about children — not someone who made something technically correct and called it done.
I think about this every time I sit down to compose for WhisperWings. Ora — who narrates the app, and whose voice was used by BMW globally in four languages — sets a standard of warmth and presence that the music has to match and support. The music isn't there to be impressive. It's there to disappear into the background of a child feeling safe enough to close their eyes.
That's a different job than any other composing I've done. And it requires a different part of you to do it well.
What Doesn't Work
A few things I've learned to avoid:
Melody with too much forward momentum. A great lullaby can be deeply memorable — that's often why it works. What you want to avoid is melodic energy that pulls the listener forward rather than settling them down. The melody should feel like an arrival, not a journey. Resolved. Circular.
Harmonic tension without resolution. Unresolved chords keep the brain alert, searching for where the music is going. Sleep music should resolve gently and consistently.
Sudden dynamic changes. Even a small crescendo at the wrong moment can jolt a child back to alertness. Every dynamic change should feel inevitable and gentle.
AI-generated music. I'll say this plainly: I've heard it used in this space and the results are consistently flat. There's something the human ear detects in AI music — a quality of having been constructed rather than felt — that keeps a faint alertness running underneath the listening. For sleep, that's the opposite of what you need. Parents feel it even when they can't name it. Not to mention, that current AI music has a sharp and brittle sound it emits around 5000 hertz that awakens the child and keeps them from sleeping.
What This Means For Your App
If you're building in the sleep or wellness space and you're using library music, the question worth asking is: does this music feel like it was made for us?
If the honest answer is no — that it fits, but it doesn't belong — that's worth paying attention to. The music is load-bearing in a sleep app. It's not decoration. It's the product.
I'm happy to talk through what original music could look like for your platform. Twenty minutes, no obligation.