I, myself, do not listen to recorded or live music during the 3 weeks, especially during the 9 days. A friend of mine who is a professional musician, who I believe is Torah observant since he made Aliyah to a religious community where I met him keeping Shabbos there, dresses with a kippah and tzitzit, etc. had a free, live concert today (5 Av) on Facebook. Are music performances permitted for parnassah? Since it was free, the parnassah were not tickets. I am thinking that he is promoting his CDs, bookings after COVID19 (His manager was endlessly asking the audience about getting gigs as I watched for minute with my sound off.) He plays secular guitar music with singing, if that is relevant. Thank you,
It's better for your friend to ask the question, since the answer depends on several subjective factors.