The Internet Archive has a project going in an attempt to save as many old sound recordings as possible. These are songs recorded on 78 rpm records made between 1898 and the 1950s, when 33 and 45 rpm records replaced them. These old records were pressed in shellac, which becomes very brittle after a few decades. The Great 78 Project invites people to digitize the music on these records, so they can be kept in a playable format for posterity. No, we don't know how long digital formats will last, but it's a step in the right direction for preservation. You can help by digitizing old records, sending in your existing digital copies, or donating your 78 rpm records. You can also volunteer to research and catalog the songs in the collection. But the best part is that you can listen to the 25,000 or so recordings that have already been digitized. They range from symphony recordings to political speeches, from Broadway tunes to hymns, from early jazz to novelty songs. Some suggestions:
"House Of The Rising Sun" (1942)
"Over The Rainbow" (1939)
"Original Jelly-Roll Blues" (1929)
"16 Old Ladies Locked In The Lavatory" (1949)
-via Kottke