Here is the site for "number 1 hits" in a given year
At the bottom of the page are links to several other groupings of songs, including Country and Pop.
Find a song, open that link and you will get a standard format song sheet. Many also have links to midi files on the song, quick and easly but I find YouTube a better source for the audio
Warning -- if you just Google for Betty Lou songs, you will get her standard home page and there is no link to country songs, or the #1 hits page.
Lots of songs in a number of genre's, including international songs.