 With the exception of harmonium by Abbey Road engineer John Kurlander on "Songs of Praise", all the instrumentation on "Boulders" was played by Wood, who also provided all lead, harmony and backing vocals.A total of nineteen instruments are credited to Wood, including cello, steel guitar, mandolin, cittern, bouzouki, double bass, saxophones, brass and bassoon.Due to Wood's very heavy input, the record was described upon release as a rare true example of a solo album, departing from other artists' solo albums where session musicians are employed.