In Harmony's Way

"In Harmony's Way", released as "Into Harmony's Way", is the seventh episode of the twelfth season of, and the 217th episode overall. It first aired on December 8, 2013.

Synopsis
"When Peter and Quagmire discover that their singing voices create beautiful harmony together, they form a singing/songwriting team, in the vein of Simon & Garfunkel. However, tensions run high when fame gets to Peter's head."

- The Futon Critic