Why did the musician get arrested?

This musical quip orchestrates its humor through a clever symphony of wordplay. The setup, hinting at a musician's legal woes, immediately sets the stage for a pun-filled punchline. The phrase 'major key scandal' brilliantly twists a fundamental music theory concept – a 'major key' being a specific scale structure – into implying a very significant or serious transgression, a 'major scandal' in the everyday sense.

The comedic crescendo arrives with the second layer of wordplay: 'in treble.' Here, the joke plays on the musical term 'treble,' which denotes a high-pitched range of notes, often associated with the treble clef. This is expertly swapped for the sound-alike word 'trouble,' perfectly conveying the predicament of someone who has been arrested. The humor lies in the unexpected, yet perfectly fitting, musical twist on common legal phrases, creating a lighthearted blend of harmony and hijinks that only a musician could truly appreciate.