To watch a concert, you can buy a ticket and go to the opera, but which will take much time and money.
Instead, you can watch it online, whether on your lap top, table computer or mobile phone with some free web apps.
Switchcam is such a web app for you to watch concerts online free.
On the website homepage, you can filter the concerts by featured, new, top genres or popular, you can browse the concerts by genres, artists or names, and you can also search for concerts.
Every concert is divided into multiple videos, which are all from YouTube, and basically, every video is for a single song. You can watch the entire concert from the beginning as default, or select a section from the left "Songlist" column to watch; for some sections, there are even different versions for your choices.
Besides to watch concert videos, you can also see who create the concert events, where the YouTube videos are from, and the similar concerts if any in the right sidebar, as what you can see from the following image.
After login with your Facebook account, you can add comments on the concert, share the concerts you watch on Facebook, and even add your own concerts.
As a beta version, Switchcam does well for you to watch Britney Spears, Lady Gaga, Miley Cyrus and many other artist concerts online free. But there is an output bug during my test, as what you can see from the following image:
Hope the above bug doesn't affect your mood to watch your favorite concerts online.