I've known Bryan Adams's birthday since the early 1990s, when he had a long-running Number One hit ("Everything I Do, I Do It For You"). I only found out Ryan Adams' birthday about 5 years ago and I was surprised that two totally different singers with phonetically similar names shared the same birthday (although 15 years apart).
Other singers celebrating today include Art Garfunkel (75 today) and Peter Noone, former lead singer with Herman's Hermits (69 today). There may be a few more, but those are the ones I know off the top of my head.
I'm sure you've heard Bryan Adams before. He's a well-known Canadian singer. In 1991, he had the biggest-selling single of the year in the USA and the UK with this song:
Ryan Adams is an American singer who hasn't been as successful as Bryan Adams, but he is still fairly well-known. This was one of his hit singles:
Ryan Adams is not really my cup of tea, although I have heard worse and that song isn't bad. As for Bryan Adams, I first bought one of his albums (on vinyl) in 1984 and I saw him live in 2002. I now have several of his albums on CD.