Colin Edwin Balch is an Australian musician, specialising in fretted and fretless bass guitar, double bass and guimbri. Edwin first came to public attention as a member of the British progressive rock band Porcupine Tree, in which he was bass player from 1993 to 2011. Currently, Edwin is a member of Ex-Wise Heads, a long running collaboration with multi instrumentalist Geoff Leigh which mixes ethnic, ambient, and post-modern influences. He is also a member of metal-influenced project Random Noise Generator, and the bands Metallic Taste of Blood and progressive metal act O.R.k., as well as participating in numerous collaborations and releasing solo work.