They have chosen to show parth and majhari's interest in music because our FL is into music as well.
Akshu being a trained singer herself will push manjhari and parth to follow their passion and earn self respect. Parth's wife doesn't seem to be a person who will resent his music profession, its only cos parth is doing nothing that she is getting irritated by him. And akshu is good at encouraging people to follow their passion, so parth will get that moral support from her.
As for manjhari, well she needs confidence boost - one of the easiest way is akshu asking to perform a duet with her. She will become famous and rest of the eorld, especially abhi will be proud of her, though Birla mansion will go nuts. But the point being this is only possible if aksu becomes part of the Birla Asylum mansion. So at some point of time, they will get abhi and aksu marry, else how will akshu help them out like akshara use to help her in-laws.