Whilst growing up in Canberra in a musical family the sounds of the Hammond organ originally captivated him, and so began his journey as a musician. "I started playing drums with an interest in The Shadows, and then Jimi Hendrix's Mitch Mitchell really inspired me with his jazz style. I think Santana had the same effect and the guitar playing seeped in to me as well, although, musically I think of Pink Floyd as my template for a band".
Peter was 12 when he became the drummer at school in a rock band called Bacchus Marsh. He then learned guitar from the members of this early group. Later, with another band called Timelord he played guitar, rehearsing in a local church hall. Steve Kilbey, who would later become his colleague in The Church, had a glam rock band called Beyond Beavers that would play there too. An invitation came in 1974 to replace one of the two drummers with Steve's band after they witnessed a drum solo he played on his drummer's kit.
Peter joined, but the singer left and they became Precious Little, with Steve on vocals. Soon after, he reverted to guitarist as they transmuted into Baby Grande, with the addition of guitarist Dave Scotland and friend Joe Lee on bass. This two and a half year collaboration eventuated in some recordings, but he left to go to college studying electronics and engineering.
After 12 months he decided to sell up and go to England/Europe for a year with a guitar, whence he began writing folk songs. Significant time was spent in Stockholm, Berlin, and London as well as on a tug boat on the waterways of Holland. An Eastern musical influence that appeared on his 1992 album Water-Rites may have been as a result of 2 weeks spent in Morocco.
As well as his contributions to The Church, he has also released several solo albums, and albums with his group The Well (1989-1995), which largely occupied his time on hiatus from The Church. The Well featured former Church drummer Richard Ploog on drums, Anthony Smith (inaugural keyboardist for Flowers/Icehouse) and Jim Leone of The Celibate Rifles on bass. The Well played live and recorded songs that were released as an EP called Iridescence and later the fan favourite solo album Water Rites.
There was still contact with Steve Kilbey, who asked Peter to play guitar on some songs for albums he was producing, Australian artists Margot Smith's Adored and Lifetime,Stephen Cummings' Everything Breaks Your Heart, and Canadian Mae Moore's Full Circle. Koppes collaborated on songwriting with singer Margot Smith, and played in her live band. (Steve Kilbey and Tim Powles also co-wrote, played and/or produced some of Smith's material on her first two albums Sleeping with the Lions (1993) and Taste (1998).