SATURDAY MORNING CARTOONS: Cookie Carnival (1935)

The voice of the hobo cookie is former circus clown, animator, gag man, songwriter, voice artist and future Bozo the Capitol Clown himself, Pinto Colvig...

CLOWN ALLEY: John Robinson Circus, Wedding Gag (undated)

HARRY NELSON: Ringling Bros. and Barnum & Bailey, Madison Square Garden (March 18, 1961)

Clown Harry Nelson with Ringmaster Trevor Bale.

PAUL WENZEL: Clown Alley, Madison Square Garden (1957)

BUMPSY ANTHONY: Paul A. Miller Circus, Harundale, Maryland (July 3, 1959)

BOWIE

CLOWN BAND (Circa 1910-20)

If I had to guess I'd date this as somewhere around the time Ringling combined with Barnum & Bailey in 1919.
Spader Johnson is at the far left, that may be Jack Le Clair seated next
to him with Pat Valdo seated to his right behind the bass drum.

A link to a Sarasota Herald article stating that Valdo did indeed play trumpet in the clown band (with a nice piece on Paul Wenzel causing mischief) can be found HERE.

JOE JACKSON: Charlie McCarthy Day (1939)

Joe Jackson with Edgar Bergen & Charlie McCarthy on "Charlie
McCarthy Day" at the New York World's Fair on July 10, 1939.