Lead sheet player: hear the melody, the chords and the bass

Updated 26 October 2026

The gig is tomorrow. Today you got a stack of lead sheets – a melody line, chord symbols above it, maybe a D.S. al Coda at the end – and you don't sight-read well enough to hear them in your head. Upload them to Duly Noted and each one plays: the melody, a comp from the chord symbols and a bass line. Mute the melody, loop the bridge, and practise over the changes tonight.

What a lead sheet gives the app

A lead sheet is the most compact way to write a song: one staff with the melody, chord symbols above it, and the road map – repeats, endings, segno, coda – to say how the form goes. A notation program would play only the melody. Duly Noted reads the chord symbols too and turns them into an accompaniment, so you hear the song.

Three parts, each one mutable

• Melody – the notes on the staff, as written. Mute it when you want to play or sing the tune yourself.
• Chords – voiced from the symbols: Dm7, G7, Cmaj7, A7♭9, slash chords like F/A. Mute them to hear the melody over the bass alone.
• Bass – a line under the chords, following the roots and the slash-chord bass notes. Keep only this one and you have a bass player to comp with.

The form is followed as written: the repeat of the A section, the second ending, the jump back at D.S. al Coda and out through the coda. You hear the whole chorus the way the band will play it.

A night's practice, step by step

1. Upload the whole stack. Photograph each chart with the phone, or upload the PDFs. Several pages of one song go in together; each song is read in about a minute.
2. Listen through once with everything on, following the highlighted bar. Now you know how each song goes – form, feel, where the hard bit is.
3. Loop the hard bit. Click the first bar of the passage and shift-click the last (on a phone, tap the bar). Slow it down until you can play it, then bring the tempo back up.
4. Mute the melody and play it yourself over the chords and the bass. For the solo section, loop the changes and blow over them as long as you like.
5. Transpose if the chart is in the wrong key for your horn or your singer – see transposing sheet music.
6. Tomorrow, on the phone. The same library is on your phone, with your corrections. One last listen in the car.

Chord symbols: read, played, correctable

Chord symbols are the hard part of reading a lead sheet by machine. They are printed in handwriting-style fonts, they sit close to the staff, and C7, C7♭9 and Cm7 look alike to a text reader that does not know music. Duly Noted reads them with its own recognition, checks each one against the melody and the neighbouring chords, and plays what it found. When one is still wrong, you click the bar, type the right symbol, and the comp changes at once. The correction is kept with the song.

What reads well

Printed lead sheets, fake books and songbooks with chord symbols read very well, as do single-line parts. Handwritten charts are not read yet. Piano-vocal scores read too, with the piano part played as written rather than from the symbols. PDFs, photos, scans and MusicXML files are all accepted.

Common questions

Does it play a style – swing, bossa, ballad?

The comp is a plain accompaniment voiced from the chord symbols, with a bass line under it: enough to hear the changes and practise over them, not a backing band with drums and styles.

Can I change the voicings?

You can correct the chord symbol in any bar, and the voicing follows the symbol. Individual notes in the comp cannot be edited.

Can I slow it down without changing the key?

Yes. Tempo and pitch are independent – half tempo is still in tune.

Can I try it for free?

Yes. Your first piece of up to 4 pages is read and played for free, with no card needed. Loops, tempo changes and transposing – and the rest of the stack – come with €3 for 3 pieces, or €5 a month for as many as you like – see pricing.