When I started playing bass I used my thumb. Then 4 months ago I started using my index and middle finger. now I've also been using my 4th finger. seem to be able to play above the jazz pu and seems to add a slightly different voicing and more color. anyone play like this on here and are there any youtube or instructional info on this? is this ok to play like this? anyone playing with 4 fingers? might be too busy I think?