Check your source more carefully: In the earlier part of the conversation with Leroy Anderson, Anderson characterizes Fiedler as a utility man in the orchestra playing organ, piano, celeste, bass drum in addition to his official position as violist.
After that Fiedler mentions that he also played double bass.
On May 6, 2014, at 8:43 AM, Loftus Becker wrote:
> I do not doubt the studies, but I think Fiedler was primarily a double bass player before he started conducting. Source: (a) conversations with musicians in Boston, ca. 1965; (2) statement by Fiedler in a conversation between him and Leroy Anderson,
> On May 6, 2014, at 12:00 AM, ARSCLIST automatic digest system <[log in to unmask]> wrote:
>> Subject: Re: Dora Labbette, Soprano with string quartette: The Flowers of the Forests, 1925?
>> I just looked up Fiedler in Wiki, and while born in Boston, his parents
>> moved to Europe (Vienna and Berlin) and he studied violin with Willy Hess
>> at the Berlin Hochschule. I didn't see mention of the Johann Strauss III's
>> orchestra, but that is possible. I might be wrong about his playing the
>> viola. Monteux was a violist, and both Reiner and Mitropoulos were
>> pianists. We have a recording of Mitropoulos performing and conducting a
>> Prokofiev concerto.