Motown
Concise Oxford English Dictionary © 2008 Oxford University Press:
Motown /ˈməʊtaʊn/
▶noun trademark soul music released on or reminiscent of the US record label Tamla Motown.
– origin 1960s: shortening of Motor Town, nickname for Detroit, where the record label was founded.
'Motown' also found in these Oxford entries:

