Lead sheet notation is commonly used in contemporary music. Whereas traditional notation shows every note played by specific instruments, lead sheets generally show only a single-line melody, chord symbols, and sometimes lyrics, like this, and the whole band shares the same lead sheet:
The chord symbol indicates the chord root, quality, and any additional notes. I’ll talk about them in more detail in another blog post.
Any musician can use a lead sheet to develop their part—sax, keyboard, drums, or whatever. And this is a great difference between (most) classical music and (for lack of a better word) contemporary music: with a lead sheet, every artist is encouraged to create their own interpretation and arrangement, and every performer will create their own part to add to the arrangement, whereas in the classical world, this job was mostly undertaken by the composer, who also acted as an arranger. While fully notated arrangements are still sometimes circulated in contemporary groove-based music, the ability to interpret a lead sheet is a component of musical literacy in many genres.
The roles of different instruments varies in a groove, and so different instrumentalists use lead sheets differently. The actual melody will only be performed verbatim by a melodic instrument or singer. But a bass player, for example, has a different job, in a groove. Bass parts need to outline the harmony, so the bassist will look at the chord symbol rather than the melody and generally play the chord root on beat 1 of every measure, and otherwise create a bass line that supports to the chord.
On the other hand, a keyboard player might create a part using the chords shown, as the accompaniment. If the band doesn’t have a bass player, the keyboard will likely play the bass part. But if the band has a bass player (or tuba player, or other low-end instrument responsible for the bass role), the keyboard might focus more on chords, so as not to muddy up the bottom.
A drummer would mostly ignore the chord symbols, though possibly notice the song form that they outline and be aware of where fills might be needed to signal a new section. A melodic instrument who is not playing the melody might create short melodic background fills based on the chord symbol and key signature, and looking for “openings” in the melody, where to fill in the groove.
So, the way the above lead sheet might be interpreted by the band just suggested might look like this, for the first four bars.
But a different group, say a trio with banjo, tuba, and singer, might instead interpret the very same lead sheet like this:
Chord symbols show the harmonic regions, and they stay in affect until the chord “changes” to a new chord (hence the term “changes,” for chord progressions, if you want to be a hep cat).
Beyond chord symbols, instrumentalists look at the key signature to see what notes and which ones are to be avoided. The relationships between chords, keys, and melodies is a study known as “chord scale theory,” and we continue to publish books mulling over the infinite possibilities of this vast topic. But to simplify, in the above example, the key signature is G, so for the chord D7, someone trying to choose notes to play there would consider both. The bass (or tuba) would be sure to play the note D prominently, and a melodic instrument would likely try to include the C (7th of D7), to give the chord its unique characteristic quality.
So, lead sheet notation is a different paradigm than classical notation, where every note is spelled out. With a lead sheet, different artists can create entirely different sounding renditions of the same “song.” Particularly in jazz, these unique interpretations are essential to the art.