English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up.
Sign up to join this community
If someone were to ask what your favorite band was, which of the following would be correct?
Who is your favorite band?
What is your favorite band?
I feel like this is obfuscated by groups named after the lead singer. For instance, "Dru Hill" or "Sisqo" would not be a proper answer to "What is your favorite band?" as they are individuals.
A band is a group of people making music. A group is a thing or entity, not a person.
Ergo, "Which band is your favorite?"
And no who's, that's what Horton hears. [joke]
Who is: singular (a band is a group of people).
Who are: awkward.
The correct way of putting it would therefore be:
What is your favorite band?
Or, if you truly wish to be anal about it:
What is the name of your favorite band?
'Whom' is your favourite band might be the most awkward, but most correct, option.
As you are talking about 'bands' rather than string quartets, most answers will be skewed towards more conversational English, in which 'Who' is fine, and 'What' is strange as it objectifies: if you really love the band, you will treat them as individual people (who), not a collective noun (what).
