Here’s a great site for using songs to help the teaching of Science in the classroom. Simple Science has videos for many KS2 topics with songs, and also explanations of some of the concepts.

Videos are hosted on Vimeo, which means they are higher quality than YouTube, and also means they are accessible in schools that have blocked YouTube.

The videos are free on the website, but if you like them, you might want to buy a DVD of the high quality versions.

4F Electricity Song from Simple Science on Vimeo.

Here are some suggestions for music that could be used to introduce a Science lesson.

Scientist – Dandy Warhols
Birdhouse in your Soul – They Might be Giants (for electricity)
Particle Man – They might be giants
Ray of Light – Madonna
Man on the Moon – REM
The Sound of Silence – Simon and Garfunkel
Walkin on the Sun – Smashmouth

On a more classical slant, for Space check out the Planets Suite by Holst such as Jupiter, or for classification try Carnival of Animals by Saint Saens. Good cross curricular links with music too.
 

You should be able to find these on ITunes and most probably YouTube too…. although the videos may not be appropriate to show though (or accessible in your school)