I ran a search in the forum hoping to find an answer to my question but with no success. Is it known whether Ms. Kendall actually played the trumpet in that scene herself or was it dubbed by a session musician and if so, is it known who it was?

Writing From St. Augustine, Florida

Being a French horn player myself, I know that Ms. Kendall absolutely did not play. Her mouth and her fingering is all wrong - not to mention the lipstick. I do love that scene though! (Don't know who really did the playing)

Writing From Alaska

Thank you. I suspected as much but am somewhat crestfallen all the same. One reads 'authoratitive' comments like, "Wasn't she terrific in the trumptet playing scene? Who knew?" etc.

I remember reading somewhere that the trumpet solo was played by Kenny Baker, who was in Ted Heath's band, as well as leading his own group Baker's Dozen. The trumpeter in the film is an actor, who's name eludes me at this time, but usually played small roles usually either a gangster or a GI. He is in the Ealing Film "The Sea Shall Not Have Them".

Micheal Balfour is the trumpeter's name

Sorry Tom,
It was Kenny Baker.
Regards Alastair

Have always had the opinion that the real player was Harry James but unless Kay Kendall had found a way to play notes whilst breathing in then I am sure it was dubbed.

Writing From Australia

According to The Internet Movie Database it was the uncredited Michael Balfour.

Kay Kendall's trumpet playing was dubbed by Kenny Baker. Kenny's Baker's Dozen jazz group toured throughout the UK until very recently. His group is one of Britain's most well known jazz ensembles. The group featured weekly on BBC radio for many years in the 1950s and 1960s.
Hope this clears this up for you.
Regards, Alastair Fyfe, Sydney.