Is there a jukebox/editor that can play just a "sample" ("hum me a few
bars") of each song in a Library.
Ideally, the sample start time and duration should be settable. 
Example - assuming a library of 3-min. songs -
the sample could be set for, say, 1 min. (start) and 15 sec. length.

Example of software that CANNOT do that,
Windows Media Player, RealPlayer, MusicMatch Jukebox, WinAmp, Nero
Wave Editor, mp3DirectCut, WavePad,
and hundreds of others.