I thought I'd share this Sexy Smooth Groove Backing Track in A Minor I've been having fun with - it's perfect for those real dirty blues guitar vibes on the A minor pentatonic (blues) scale!!
The progression is Am - D7 - Fmaj7 - E7
In terms of scales, you could use:
* A Minor Pentatonic Scale: A C D E G (A)
* A Dorian Mode: A B C D E F# G (A) - Am and D7 chords
* A Minor Scale (Aeolian Mode): A B C D E F G (A) - Am and Fmaj7 chords
* A Harmonic Minor Scale: A B C D E F G# (A) - E7 chord
PS. There's more great blues jam tracks at http://www.quistorama.com/blues