This is a song that I used with my 4th graders when we learned about reading the music staff. In my approach, I decided that I wanted my students to first be able to find an A on the music staff, then use the alphabet to find the other letters.
We sing this song every day during this lesson sequence (and during recorder) to reinforce where A is on the staff. The chorus repeats the phrase "Second Space A" three times and the verse reminds the students of other useful information about reading the music staff, such as the note names for the lines above and below A.
I find this to be a more effective note-reading strategy than traditional "Every Good Boy Does Fine" or "Spaces Read FACE" methods. Try using this song with your 3rd - 5th graders when they learn to read the staff!
Included in this download is a PDF file of the song and a piano part, if you want to accompany your students. Additionally, there is a backtrack that I created in GarageBand, if you would rather simply play a track.