Practicing with Music during Sefirat Ha-Omer

Question: Our Bnei Akiva Shelichim would like to do have Israeli dancing leading up to a Yom Ha-Atzmaut celebration. Is it permissible to have the classes with recorded (not live) music during Sefirat Ha-Omer? Answer: No. They should either practice before Sefirat Ha-Omer with music or during with accapella.