Don, I was only referring to Jazz. Although BC actually started his career as a singer for so-called (i.e. self-styled) Jazz bands -- well, just listen yourself.

In his own genre, Crosby filled the role well. According to Wiki, he even invented the typical devices that were later copied by other "crooners". I also agree with you and leeneia that a well-calculated deviation from the written dots can add greatly to the message. "Tasteful" is a matter of taste; "in style" would be my words.

And yes, singers of folk songs, pop ballads, chansons etc. can learn from him, provided they know their own style. Jazz and classical singing obey stricter rules, but within these, the best singers can convey a lot of emotions to fit the lyrics. Many others sound machinelike.

I asked an expert on true love whether she would melt away for Crosby, and she denied. Leeneia, he's yours ;-)