All that can presently (May 2013) be gleaned about by internet searching is that Henry Widmer is the one-off composer of Pickin' on De Ole Banjo (1915).
Surfers are welcome to contribute information about this composer.
This list is arranged in chronological order and contains 1 work by Henry Widmer.
It does not claim to be complete and represents only the number of items located. Keys:ER