Thanks for that. I should have been clearer about what I meant. I was, in my mind, defining a singer as someone who might be putting out solo albums and playing cabaret or concert engagements...someone who makes a good part of their living just as a singer, as opposed to an actor who sings sometimes. But I didn't actually write that in the post.
I would classify Garber (and the other Applegates that I mentioned) as actors who sing. None of them would likely be fronting a symphony for a Broadway concert or appearing at 54 below in their latest solo cabaret show. None of them record solo albums.
The larger point is that I feel like Bryan Cranston should chill out...there are so many better things he could devote a couple of years of his life to than doing intense vocal training to play Applegate. It's actually probably more a lack of confidence than anything else. Maybe singing in public terrifies him to the point that he's built this role he'd like to play in his own mind into something akin to Sweeney Todd.