Why use bells and whistles?

SEELEY LAKE – If Joe bought a fancy new computer, he might boast to Cindy, "It has all the bells and whistles." Nevertheless, if Cindy were to take apart his computer, she would find neither a bell nor a whistle among the pieces of hardware. So how did this phrase, meaning fancy additions beyond those essential to the use of the item itself, come into being? No one knows for sure, but that does not keep anyone from speculating.

One theory connects the phrase with trains, especially steam locomotives, which used a whistle as a sort of shorthand messaging system. Three short bursts from a moving...