/diy/ - Do It Yourself

i'm trying to parse analog audio using an arduino, a 3.5mm jack input. using a multiplexed equaliser such as MSGEQ7 would be ideal, but no stores around me have it and if I ordered it online it wouldn't arrive in time for what I need.
so i'm left with using arduino's analog input pins directly. has anyone done something like this? first thing i would need to do is shift the signal +2.5v from -2.5v-2.5v to 0-5v, since the arduino can't read negative voltage, right? any tips appreciated