They both got their start in theater. They were both in the original cast of Phantom Of The Opera.
Sarah Brightman had a couple of albums singing showtunes. The two I remember hearing on radio were: All I Ask Of You (duet with Cliff Richard) and Love Changes Everything.
This is the album those two songs are on: http://www.amazon.com/The-Andrew-Lloyd-Webber-Collection/dp/B00000I0XW/ref=sr_1_7?s=music&ie=UTF8&qid=1333506607&sr=1-7
Now, Sarah Brightman is singing classical music.
Michael Crawford's albums consisted of showtunes and some easy listening pop ballads.
From this album, I remember hearing his version of When You Wish Upon A Star on radio: http://www.amazon.com/Songs-Stage-Screen-Michael-Crawford/dp/B000002IUD/ref=ntt_mus_dp_dpt_8
These two contain his easy listening pop ballads:http://www.amazon.com/Touch-Music-Night-Michael-Crawford/dp/B000002IWS/ref=ntt_mus_dp_dpt_10http://www.amazon.com/With-Love-Michael-Crawford/dp/B000002IUI/ref=ntt_mus_dp_dpt_13