Longbranch Pennywhistle was a country rock/folk music group featuring Glenn Frey and John David Souther. They released a self-titled album in 1969 under the Amos Records label. Both had made the migration from Detroit to California and were adapting to what would become the California sound.
When the Amos Records label dissolved in 1971 the group had already disbanded the year prior. 
Glenn Frey went on to co-found the Eagles and J.D. Souther wrote or co-wrote several of the Eagles' most popular songs, along with hits for Linda Ronstadt. He also recorded a number of hits under his own name, including "Her Town Too" which was a major hit in a duet with James Taylor.
On March 16, 2018 it was announced that their only album has been remixed and remastered and would be reissued as part of the Glenn Frey greatest hits collection Above The Clouds on May 11, 2018. A standalone CD and Vinyl Record was released on sept.28,2018