The major 7th and minor 7th chords sound very luscious in a jazzy kind of way. When used correctly, they can spice up a blues progression very nicely. Take note that you can’t play an A minor pentatonic scale over A major 7th. You won’t have these kinds of worries playing over the minor 7th chord. It will soak the pentatonic minor and minor blues scales you are used to playing right up.

Here’s hoping you have continued success in your musical development.