"Summertime"

Guitar chords

There's the introductory electric piano part, and then the bass has a section almost all to itself (there's a bit of sustain from the electric piano part) before the guitar and drums come in.  For that part, there's an introductory A minor | E major | B minor | E major before the verse properly starts (although the vocals start on that last E major).

Verses:

|: A minor | E major | B minor | E major :|
D minor | F major | E major
|: A minor | E major | B minor | E major :|
C major | A minor | F major
A minor | E major | B minor | E major

During the electric piano solo:

A minor | D minor | A minor
C major | A minor | F major
A minor | E major | B minor | E major

After the final verse, there's another section of A minor | E major | B minor | E major before resolving on A minor.

Bass part

With the chords written in: