well, I still htink useful to post a list ...a big, huge, ever changing list of things to jam, so that there could be ideas. These i have done with friends and others are things I have played with others on servers.
Blues all kinds, from minor to major blues and jazz y blues(, even 8 bar new orleans blues should be fun to jam to)
some jazz tunes that work a charm:
solar
st. thomas
lady bird
cantaloupe island
500 Miles High
all of me (for this one or any 32 aaba song form you need to leave BPI at 16 but halve the tempo and vbe VERY patient)
first four chords of the progression to isn't she lovely (Stevie Wonder)
Any guajira or latin music based chord progression: i-iv-V-IV for son, or the so called "phrygian" one (i-bVII-bVI-V7)
also, the first section of the song Morning, by Clare Fischer.
for now I ran out of ideas, but I am sure there are many, many more.
edit, more ideas:
summertime
when the saints go marching in
Sugar Stanley Turrentine
swing 39 (django and friends)
also, many things from neo soul which have interesting, short vamps, such as:
Jill Scott - how it'd make you feel
https://www.youtube.com/watch?v=oZP8emDMD84
and cross my mind:
https://www.youtube.com/watch?v=tKEjKhg95_g