Complex sentence: The instrumental backing track was completed by Pink Floyd but the master tapes for the song most likely were erased, however elements from the song would later become part of Barrett's solo song "Opel" recorded in 1969.
Split into simpler sentences: The instrumental backing track was completed by Pink Floyd but the master tapes for the song most likely were erased. Elements from the song, however, would later become part of Barrett's solo song "Opel" recorded in 1969.