Chord Proggression Notation

[tobie]

Some lazy piano players will notate extended chords this way like I7/V7#9 means (in C major) play a C7 chord in the right hand and G7#9 in the left which essentially adds up to a G alt. chord.

This is exactly how it has been used by keyboardists/pianists in all church bands I've played in. The preference is then for the bassist to play notes from the chord behind the slash as it reflects the bass (left hand) part. 7ths don't always sound good in such event however, so if I have not practised it beforehand, I play it safe and play notes from the chord before the slash.