How to play 7th chords on GarageBand for iPad

Garage Band for iPad is a truly fantastic piece of software. It's so good you can excuse its limitations but limitations it has.

The Smart Keyboard instrument does allow you to vary the bass note independently of the chord which means you can imply various 7th chords very easily. A CM7 chord has a B note added as the M7 part. The notes B, E, and G are simply an Em chord so you can simply play those together to imply a CM7. It works great. Here's a quick chart for you:

CM7 = C bass + Em
Dm7 = D bass + F
Em7 = E bass + G
F7 = F bass + Am
G7 = G bass + Bdim
Am7 = A bass + C
Bm7-5 = B bass + Dm

Enjoy.