To a professional singer is died a father.
He have a job, but without the money that he will gain with the singer job, (wedding and bar mitsvà) he will have a serious money problem.
He work alone and has 2 sons.
Can he sing? After 7? after 30? Now he is in 7 days of avelut, but from mid march to October he will have a lot of job…
Hamokom yinachem, eschem b’toch shar aveilei tzion v’yerushalayim.
Regarding your question, after the 30 day period it is permitted for you to play, however during the 30 day period it is controversial. Therefore it is preferable to avoid it, but if it is difficult for you you have what to rely on.
Shut Maharil Diskin Kuntres Acharon 196, Aruch Hashulchan Y:D 391-14, Igros MOshe O:CH 3-87, DIvrei Sofrim 41- 17,18, see footnotes there.