The Internet Archive discovers and captures web pages through many different web crawls.
At any given time several distinct crawls are running, some for months, and some every day or longer.
View the web archive through the Wayback Machine.
Note: Song title and
position links lead you to the song's Top
40 chart run (from the ARC Weekly Top
40)
and LP links take you to Amazon.com for that LP (often
including track listings and sound
samples).