"Musicologically, he's Janus-headed. "
A bust of Janus, on display at the Vatican museums
Public DomainA bust of Janus, on display at the Vatican museums

In Roman mythology Janus is the God of gates, entrances, beginning and endings. 'January' takes its name from Janus, who in turn takes his name from the Latin for 'archway'. He is often depicted as possessing two heads, each facing in opposite directions.