a guitar:
5 octaves (normal tunic EADGBe)
12 notes (western scale)
22 frets x 6 strings=132 notes
mininum 2 notes to a chord=17,424 chords
a "riff"=usually 2 bars in length
2 bars (common time)=
2 whole notes
4 half notes
8 quartrer notes
16 8th notes
32 16th notes
64 32nd notes
128 64th notes
doesn\'t account for scale, mode, key, odd time, tuplet, or any other instrument except 1 guitar. point being, there are plenty of options and it has not "all been done"