The Beach Boys , with help from Winfrey , sang the backing vocals .
Brian added sound effects including hitting an empty 5 - gallon Sparkletts glass water container with a rubber mallet for percussion , footsteps and the horn of his Rolls - Royce Phantom V .
The Beach Boys , with help from Winfrey , sang the backing vocals , and Brian added sound effects including hitting an empty 5 - gallon Sparkletts glass water container with a rubber mallet for percussion , footsteps and the horn of his Rolls - Royce Phantom V .