The phrase 'Having It Large' can refer to many things, the most common use is when referring to
something enjoyable, for example: 'I'
m having it large
later!' - 'I'm gonna have a good
time later!'
Although a new modern musical use for the word has also recently arisen where you 'Have it Large' on a variety of instruments by making as much noise as possible but in a melodic fashion, rather than just hitting whatever you can and thus creating what may be described as a 'Racket'...
One of the instruments most widely used for having it large is a Drum Kit, mainly due to its high volume levels and variety of sounds.
Another interpretation of the phrase is to
play music as loud as possible.