Tim Valdes, an eclectic and versatile musician who performed, recorded, composed, and played over fifteen instruments, including tuned and varied percussion, tabla, drum set, banjo, and several other stringed instruments, died of cancer in November 1990; "Sudden Dusk" by However is dedicated to him (https://www.youtube.com/brFXcTIssHU).

Tim joined the progressive rock group, However, from the late summer of 1977 through spring 1978, according to this timeline at howevermusic.com. 

Tim also played with Stitch In Time, a local folk rock band.  Tim Valdes is pictured here (far left) with band mates, Don "Whitz" Berkemeyer, Terresa Gayle, and Peter Princiotto.  1984, McLean, VA

Here (from Youtube) is Tim playing banjo--his back to us--in this recording from the Fort Hunt High School "The Entertainers" Talent Show, Saturday, June 7, 1975: