Solar by Miles Davis is not really an easy tune due to the quickly changing key centers that stay for increasingly shorter times. It is also mostly played at higher tempos.
Alone Together (Arthur Schwartz) is a popular jazz standard that is mostly played as a ballad (as it was originally intended), but can also be played at higher tempos.
Sunny is an immensely popular tune by Bobby Hebb. Few people however know the original version. The changes are very simpel and you can get away with using only the A minor pentatonic for your solos (C concert instruments).
This backing track pack is mostly geared towards people that want an accompaniment without chords so they can play in a trio setting (you + bass + drums). This is especially the case with pianists who accompany themselves and guitarists wanting to play the chords.
Bluesette is an “original” composed by Toots Thielemans.
Ah, So What! I don’t know if Miles Davis knew that by composing So What he would change the face of jazz forever (I think he knew). So what is again deceptively simple to improvise over. Just two chords/ modes: D minor dorian and Eb minor dorian (I know dorian is always minor, but just to be clear…).
Another classic: Autumn Leaves (Joseph Kosma). The song is a standard played to death at jamsessions and music schools. With reason…