In blues ‘dominant’ 7 chords (A7 or D7 for example) are more common than basic major, minor and sus chords. The A7, D7 and E9 ...

You don't need to know many guitar scales to play guitar solos ... to see that the C major pentatonic scale uses all the notes from a C chord, plus a couple of extras. Play through the chord ...

All the chords built on other notes in the scale of C are minor, except chord VII - the notes B – D – F, which is diminished. When a seventh is added to a chord this is known as a seventh chord.