Final answer:
Men did not frequently join the nuns' choir in convents to perform the bass parts.
Step-by-step explanation:
In convents, men did not frequently join the nuns' choir in order to perform the bass parts. This is because convents were religious communities for women, and typically men were not allowed to participate in the choir or other activities within the convent. The nuns themselves would have sung the various vocal parts in the choir, including the bass parts, if needed.