I've never been to a nerdcore show but I have no reason to believe they'd be very good. The nerdcore ethic is very DIY and it is aimed for the nerd/geek audience so non-fans would likely be bored. A lot of the nerdcore rappers do most of their stuff in the studio (which is most likely their bedroom), where they have a lot of control and can play and tweak with the sound till it's perfect, but when faced with a live audience the experience may suffer from the studio perfection. There's also the chance that MC Frontalot isn't good live.
Anyhow I just downloaded this little baby:
The Seatbelts -
Cowboy Bebop
Music from the amazing anime series, full of '40's and '50's bebop jazz and early '60's rock.