"Bridge over Troubled Water" was the final track to be recorded for the album but the first completed, with an additional two weeks of post-production. Simon initially composed the song in G major, but arranger and composer Jimmie Haskell transposed the song to E-flat major to suit Garfunkel's voice. The song was recorded in California, to make it easier for Garfunkel to go to Mexico to film "Catch-22". Simon wanted a gospel piano sound, and hired session musician Larry Knechtel. Joe Osborn played two separate bass tracks, one high and the other low. A string section entering in the third verse completed the arrangement. The drums were played by Hal Blaine in an echo chamber to achieve a hall effect and Los Angeles session percussionist Gary Coleman played the Vibraphone. The arranger Ernie Freeman labelled his string arrangement as "Like a Pitcher of Water".