Do the mourning customs apply during Chol Hamoed Pesach according to those who mourn until Lag BaOmer?
Some Poskim[1] rule that the mourning customs apply during Chol Hamoed, and hence one may not dance or listen to music. However, other Poskim[2] rule that one may dance and hear music during Chol Hamoed Pesach and so is the accustomed practice.[3]
_______________________________________________________
[1] P”M 493 M”Z 2 and Kaf Hachaim 493:9 regarding music that it is forbidden on Chol Hamoed; Shiyurei Kneses Hagedola 493:9 and Kaf Hachaim 493:25 regarding haircuts that those who follow the mourning period from after Pesach, may not get a haircut even on Chol Hamoed or Rosh Chodesh Iyar even if they are permitted to do so from the laws of Chol Hamoed
[2] See Az Nidbaru 10:23; Mishneh Halachos 8:188, based on Shaareiy Teshuvah 534:1 who permits music on Chol Hamoed.
[3] The reason: Perhaps the reason is because Simcha is a Biblical command on Chol Hamoed, and hence we allow music. [See Admur 529:6]