I’m always running out of disk space on whatever computer I am using, so Baseline sounds interesting:
another good option is Baseline, which offers both graphical and columnar views, along with a unique twist. Like GrandPerspective and WhatSize, you can scan a volume at any time and view the results. In List View, you can sort by name, kind, modification date, size, or size difference (more on the last option in a bit). Column view gives you a hierarchical view of your drive’s contents. As with WhatSize, in both of these views, file and folder sizes are colored based on size; for example, the sizes for items over 1GB in size are displayed in red, and the sizes of items over 1MB but under 1GB are purple. Baseline can even scan Time Machine volumes. (As with any of these space-surveying programs, you’ll need to run Baseline with root privileges to scan private directories; for example, the home folders of other users.)
but doesn’t sound like it is useful enough to pay $20 for. Especially since I’ve been using the freeware application WhatSize for many years which basically performs the same task, and occasionally have used the freeware applications GrandDesign or Disk Inventory for visual representation of my overstuffed hard drive.
and yes, I have many many mp3 files on my hard drive.
GrandPerspective color options
a quickr pickr post