Most Jazz and Fusion players use a technique called chord substitution to add different sounds to their playing. Chord substitution simply means substituting another chord for the one written on the page. This is usually done on the basis that the chord to be substituted has at least one (but usually two or more) note in common with the original chord. To substitute chords successfully, you really need to know your chords well. It is recommended that you purchase a Jazz theory book and study it until you are confident playing any chord, mode or scale in any key without having to think first. It is also a good idea to study this aspect of improvising with a Jazz teacher who will be able to show you some transcriptions of solos by great players which use chord substitution. This aspect of playing can take a long time to become comfortable with, so be patient with it.