Is it legal to put my music on full blast in the back yard during legal hours?

Seems like you could inflame the matter or find a solution. Neighbours can be a problem and it seems you need to sleep when things are kicking off. Secondary glazing and good heavy curtains will block out external noise. I've built fitted wardrobes on shared walls and the insulation when the're full blocks out any other noises. We live on a main road near a police station and hospital and believe me, the sirens are very loud but the measures iv'e advised means we get a great night's sleep. Good luck.