Tops on my list of underrated bands is NRBQ.
They have been called the world’s greatest bar band because they only
performed in clubs. They put out their first album in 1966 and
continued to crank them out on a regular basis up till about 2 years
ago when they broke up–at least for the time being. Their music style
is a unique blend of old style rock n roll, country, and bee bop jazz.
Their leader, a great keyboard player named Terry Adams, is considered
one of the world’s leading authorities on Theloneous Monk and when he
plays a solo in Monk mode the resemblance to the master is uncanny. On Terry’s latest album he does a rendition of Blue Monk. 

Two
other underrated bands are staples for those who were into the East Bay
funk sound–of course the most famous of this “school of soul” is Tower
of Power, who is still kicking and recording. But two other bands that
should be better known but are not are Cold Blood, featuring the incredibly powerful vocals of Lydia Pence, and a group called The Sons of Champlain.
Both of these groups have, after about 30 years, put out new albums in
the last year. For those of you that might possibly be fans  of
these groups, I have their new albums and they have lost nothing. Lydia
is still amazing and the horns just smoke.