Simplify the following text for a Grade 12 native English-speaking person.
Original: The track was recorded on 8 February 1967 , with overdubs ( extra music that 's recorded into the song ) on 16 February ( bass and vocals ) , 13 March ( brass section ) , 28 March ( backing vocals and guitar solo ) , and 29 March ( animal noises ) .
Simplified: The track was recorded on 8 February 1967 , with overdubs on 16 February ( bass and vocals ) , 13 March ( brass section ) , 28 March ( backing vocals and guitar solo ) , and 29 March ( animal noises ) .