I've found when doing network pentesting there's a very different set of music that works well for me compared to web app pentesting. For network testing I tend to start with movie soundtracks before moving up to rock instrumentals like east Hastings then on to harder and harder rock/metal before hitting cradle of filth.

On web app tests I normally find plaid or other ambient electronica works better for me.

For coding I find that swing, jazz and blues works best. I've been listening to a lot of cab Calloway of late which is mostly instrumental or scat focused. If theres too much by way of lyrics or if it's too catchy it tends to disrupt my concentration though.