you play notes that dont belong in the scale you are playing over and it stills sound great, for example lets say you play over C major
the notes you have are C,D,E,F,G,A,B
you play a I7-IV7-V7
that would be C7= C-E-G-Bd
F7= F-A-C-Ed
G7= G-B-D-F
you have two notes (Bd,Ed) that dont belong in C major
and if you add the bluenote Gd you have three notes,
and whats the deal with the bluenote? its a diminished 5th
this note is used by metal bands because of its "evil" sound
howcome it sounds so beautiful in blues?
Peter