Herman Sandy bought his first vinyl record, Georgia On My Mind, by Nat Gonella, in 1935. He then began studying trumpet and classical music, but was more interested in listening to Buck Clayton, Louis Armstrong and all the great American jazz musicians on the radio.
He toured in Germany after the liberation, then returned to perform in Brussels.
He played and recorded with the bands of Bill Alexander, Septette Van Bemst, Charlie Calmeyn, Jack Sels, Jacques Pelzer, etc...
While playing in Leo Souris', David Bee's and Fud Candrix's historical Belgian orchestras, he went to perform with Toots Thielemans, Sadi and Jacques Pelzer at the Nice Jazz Festival in 1948.
He played with the band of Léo Souris a the Comblain-la-Tour jazz festival.
He spent six years in the Henry Segers TV orchestra, and 17 years with the great Flemish Francis Bay TV orchestra (later Freddy Sunder's orchestra).
In 1955, he records with the Jacques Pelzer Modern Jazz Sextet, with Jean Fanis (p), René Thomas (gt), Paul Dubois (b) and Rudy Frankel (drs).
In 1957 at a Miles Davis concert held at the Brussels Theatre Patria, Miles stopped Herman after finishing his set (his band opened for Miles Davis) and asked "Was that you playing 'You and the Night and the Music' ? It was damned good!"
He appears on the legendary LP "Jazz in Little Belgium" (1958, on Decca records 123.259) in the company of Willy Albimoor (p), Constant Letellier (ts), Roger Asselberghs (bar sax), Paul Dubois (b) and Johnny Peret (drs).
In the nineties and around 2000 he plays with "Jazzfun" (Alex Scorier, Roger Asselberghs, Robert Pernet), and with Paul Dubois'.
Herman Sandy also led several bands, such as Herman Sandy’s Jazz Gang, Five is a crowd, with Vincent Mardens (saxophone), José Bedeur (bass), Jean Haurez (piano), José Wampach.
He also played with the Retro Jazz Orchestra.