P C III (Pipe Choir Three) is a musical duo started by Michael J. Bostwick and Kelly Bostwick in 2013. P C III was developed as a platform to showcase all of Michael Bostwick’s Onistwave compositions. Onistwave is a genre of music developed by Michael J. Bostwick.
Onistwave is described by Bostwick as:
1) Music created with the aim of relaxing the listener.
2) Music of an extremely long duration (a minimum of 15 minutes).
3) Very light handed minimal percussion is used.
4) Punctuating cymbal crashes are not used.
5) Is not constructed with samples or loops from external sources.
6) Music that often includes elements of pop, rock, classical, ambient, electronic, and world music.
7) Music composed with primarily acoustic, electric, and electronic instruments.
8) Music that incorporates a heavy use of keyboards and atmospheric treatments.
9) Music that often incorporates minimal but heavily layered vocal lines.

Onistwave generally pulls musical influences from Ambient, Post-Rock, Progressive Rock, Drone and sometimes even Slowcore.
P C III's music is licensed under Creative Commons Attribution 4.0 International.

In 2016, P C III released their song "The Rise and Fall of Bossanova", a 13 hour, 23 minute and 32 second piece with five sections. The song has gained notoriety for holding the Guinness World Record for longest recorded and released song from 2016 to 2021. P C's song "In The Garden" also held this record for quite some time, before being dethroned by TR/FOB and then later being dethroned by Earthena aka Tharanee's 48 hour and 39 minute piece "Symphony of the Crown" released in 2021. The song has gained some criticism among fans, due to being a compilation of mostly pre-existing pieces off of their previous three Ad Astra albums released from 2014-2016 without any changes, mixed in with some Pipe Choir and new material.

In 2020, P C III released "Onistwave Experiment #33", a 33 hour, 5 minute and 59 second piece with 11 parts. This is currently their longest song, however it was not recognized by the Guinness World Records, due to Earthena's Symphony of the Crown" coming out soon after OE#33. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.