"Las Mananitas," the traditional Mexican birthday song, can be watched and heard on YouTube in many different ways. There are several hundred videos that are currently uploaded to YouTube featuring the song, as of 2015.
Many YouTube users have recorded and uploaded videos in which people are playing and singing the song "Las Mananitas." All of them are very easy to find when you go directly to YouTube and look up "Las Mananitas" in the search bar at the top of the page. The search yields many pages of results that lead to videos that play the Mexican birthday song in Spanish.