Tower of Power (or TOP for short) is an American R&B-based horn section and band, originating in Oakland, California, that has been performing since 1968. They are best known for their funky soul sound highlighted by a powerful horn section and precisely syncopated bass-guitar lines. There have been multiple lead vocalists, the most well-known being Lenny Williams, who fronted the band between early 1973 and late 1974, the period of their greatest commercial success. Their highest-charting songs include "You're Still a Young Man", "So Very Hard to Go", "Soul With a Capital S", "Soul Vaccination", "What Is Hip?", and "Don't Change Horses (in the Middle of a Stream)".