What kind of work? Did you make "Real Instruments" recording? These may have survived the crash - GarageBand writes the recordings immediately to the drive, even before saving.
Ctrl-click your project and select "Show Package Contents"; then your recorded audio tracks should be visible in the "Media" folder, like in this example - a project before the first saving:
However, with software instruments and loops I see no help; these will only be written to your disk when you save the project, and thus, they will not appear in your Time Machine backup until you safe them.