(written from a Production point of view)
Barrie Ingham (10 February 1932 – 23 January 2015; age 82) was the actor who portrayed Danilo Odell in the 1989 Star Trek: The Next Generation episode "Up The Long Ladder". Ingham, Michael Dorn, Gene Roddenberry and Patrick Stewart can be seen heartily singing "Phil the Fluter's Ball" in a season two bloopers reel. 
Ingham played Paris in the 1965 Doctor Who story "The Myth Makers" (which unfortunately no longer exists in the BBC Archives). He was therefore one of the very small number of actors to have appeared in both the Star Trek and Doctor Who franchises. Ingham also played Alydon in the 1965 Peter Cushing Dalek film Dr. Who and the Daleks.
One of Ingham's best-known roles was the voice Basil of Baker Street, the title character of Disney's 1986 animated film The Great Mouse Detective, a mouse who lives beneath the residence of Sherlock Holmes. The film also featured the voices of Eve Brenner, Walker Edmiston, Wayne Allwine, and Frank Welker.
Ingham performed a great deal of theatre. He was the winner of the Honorary Associate Artist with the Royal Shakespeare Company, Australian Theatre Most Distinguished Actor Award, and the Drama-Logue Award for the Best Performance in a Broadway Musical.