We live in a semi detached house - we own but next door is rented out. We’ve had 6 different sets of tenants next door in the 17 years we’ve been here and never had any problems until the current ones. Really loud music (electronic dance music so heavy beat), shouting etc etc.
It affects our sitting room and 2 children’s bedrooms primarily.
Is there anything I can do to soundproof our walls which is effective, not massively expensive and won’t result in us loosing a lot of space?