Truly

How are you, truly?

Tell Truly your mood and how much energy you have. It builds a short path of classical music that starts where you are and moves, one piece at a time, towards calmer or brighter. Everything plays right here, privately.

  • Free
  • Private
  • Open source
  • Plays in your browser
See how it works Find music View on GitHub
where you are where you'd like to be

How it works

Four small steps, and you stay in charge of every one.

  1. Step 1

    Tell

    Choose your mood and your energy. It takes a few seconds.

  2. Step 2

    Choose a direction

    Calmer, gently brighter, or staying where you are. Truly suggests one, and you decide.

  3. Step 3

    Listen

    Four, six or nine pieces, as you choose, play in order, each a small step from the last, with a short note on why each one was chosen.

  4. Step 4

    Shape it

    Swap a piece, prefer piano, strings, orchestra or winds, slow the path down or stop at any time. Optional camera and voice experiments can nudge where the music starts.

Technical design: how Truly and its models are built

How the music is chosen

Truly builds each path from published research on music and emotion.

  • Every piece has a mood

    Music can be placed by how bright it feels and how lively it is. Truly places your answers on the same map.

    Russell, 1980

  • Start where you are

    Listening research suggests that starting close to your mood, then moving gradually, shapes how music feels.

    Starcke and von Georgi, 2024

  • Small steps

    Each recording has published mood and tempo scores, so every piece can be a small, smooth step from the last.

    Du and colleagues, 2026

  • A face is only a hint

    Faces and voices are not a reliable guide to feelings, so the optional camera and voice inputs only nudge the start and never decide anything.

    Barrett and colleagues, 2019
Read the research and references

Private by design

  • Everything runs in your browser, and the music plays from Truly's own site.
  • No account, cookies, analytics or tracking.
  • The camera and microphone are off until you try them. Nothing they pick up is recorded, stored or sent, and speech is never turned into words.
  • Mood answers are never saved. Saving is off unless you switch it on, and you can delete what is saved at any time.
  • Your answers are only ever used to choose music.

Open for everyone

Truly is free software, built on openly shared research, data and recordings. Developers, researchers and musicians are welcome to help, from the music catalogue to new ways to shape a path.

Source code Technical design Data and models Scope