Hello, Connie,
One of the challenges with sound recordings is that they can have substantially different durations for the same physically sized artifact.
You mention discs, as I'm sure you're aware, a 12" disc can be recorded at 78, 33-1/3, or <gasp> even 16-2/3 revolutions per minute. While a 78 side is typically one song, a 33-1/3 rpm microgroove recording might yield typically six songs and the 16-2/3 rpm disc would yield double that. I won't provide timings because there are people more knowledgeable than I concerning grooved media on this list.
As to tapes, you might find the following tape timing chart useful for reel-to-reel tapes in your collection:
http://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/analog-audio/tape-timing-chart/
The challenge here is that it is not uncommon for a 7-inch reel to house anywhere from a half hour (or less) to eight hours or more and unless you look at the fine print, you won't know.
So, conventional metrics as to the amount of content for sound recordings may not be strictly applicable.
Cheers,
Richard
At 01:18 PM 2008-11-18, you wrote:Wow what a couple of great sites! Thank you! I am still hoping for something like this for audio records. Thanks again Jeanette!
Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.