Q: Mac HD audio file storage size

OK, so I've rebuilt the Spotlight index - not sure how this has helped:

"About this Mac" still shows 157Gig of audio on the HD, while I can't find more than 69Gigs with any search.

Thanks for the help. I've rebooted, but all the values are the same. Basically, there's 100Gigs of disc space unaccounted for. The disc utility tells me that the HD is occupied by the following:

Audio - 157

Other - 147

Apps - 16

Photos - 13

Movies - 7

However, while "get info" tells me that the HD has 340 GB used, checking all the main folders in the HD reveals the following:

Apps - 16

Library - 15

System - 8.5

System folder - 1.7

Users 203

That's a total of less than 250 gigs - so where's the other 90 gone? The audio appears to be the culprit, but there's only 69 gigs of music on the HD.

Oh, I should have said, that before upgrading to El Capitan, the HD had about 250GB of data.

Thanks both. I've just run OmniDiskSweeper and interestingly it tells me that the HD has 244GB of data - which is seems right.

I just tried running it from the terminal, but it keeps asking for a password which I don't have - ie the administrator doesn't have a password.

OK, I'll set a password, reboot and try again - thanks for your help, much appreciated.

Right, got ODS to run from the Terminal (not that I had a clue about what I was doing mind you!) and it revealed where the missing 90 gigs are. My 19 yr old son is an occasional user of the family machine, and he has some very untidy habits where it comes to music files. I will be deleting without mercy!

Many thanks for your help in identifying the issue.