The Rescue Barge Barge: MP3.com Dataset
Archive.org has a sizable collection of mp3.com audio in The mp3.com Rescue Barge. 960.6 GB is nothing to sneeze at! But a few years ago I came across a big list of download.mp3.com links, many of which were already hosted on the Wayback Machine - and a great deal of them, not represented in their own Barge! To remedy this issue, as well as collect IDv3 metadata on all the audios I can find, I started the Rescue Barge Barge project to fill in the gaps with some storage loaned from a friend and then a larger drive I bought myself. The result is a hoard of 533,046 mp3.com mp3s (counting duplicates) from bitrates from 24kbps to 128kbps, totaling 1.78TB!
While I don't believe I have means to share the downloaded files themselves due to the sheer size of the archive, I compiled a huge CSV with everything one needs to look through it with the Barge + Wayback Machine source URLs, including artist, title, genre, and comment metadata. For less than relevant - but hopefully interesting technical details, see my blog post on The MP3.com Rescue Barge Barge.
MP3.com Dataset (zipped CSV, 27.5MB; 131MB decompressed)
To use the CSV, I'd recommend a newer version of Excel with CSV parsing. Make sure you check the "my data has a header" option, and set the all text columns to Text (Artist, Title namely) to prevent it from evaluating some of them as math expressions.
This spreadsheet copy already has it done for you, so you can open it in Excel / Google Sheets / LibreOffice.