Backing tracks with "performing rights"
Backing tracks with "performing rights" are, for example, all those
related to famous songs. For your message you can choose any of
famous backing track but, in order to broadcast a message
that has that music as a background, you'll have to get a licence
from the appropriate independent bodies (just as TELEPHONE VOX
has already done with SIAE) by paying them for the broadcast rights through
an annual subscription. This is what is required by
law; there are those who do it and those who do not, but not legalising
your usage is a punishable offence.