By age so who ever is the oldest is the leader
Not based on skill
Their management company SM Entertainment.
SM Town is the name of SM Entertainment's yearly concert tour.
Group LSG, also known as SNSD (Girls' Generation), was formed in 2007 under the management of SM Entertainment.
SM Entertainment, YG Entertainment, TS Entertainment, JYP Entertainment, etc
You don't actually get a 'job' at SM. First you audition for it, then if they accept you, you will audition for them once again (just in case), and then you sign contracts, and you will be a SM trainee. Then, one day you will be chosen to debut under a group that they make. Some trainees train longer than others. Like SNSD Jessica has trained for about 7 years, while SNSD Sunny only trained for 6 months.
SM Entertainment wanted a vocal sub-group for SNSD. Taeyeon, Tiffany, and Seohyun have very strong vocals.
gary glitter's gang
SM Entertainment
The most famous Entertainment Companies in South Korea are SM Entertainment and YG Entertainment. Both companies have very different styles of music so it is difficult to say what the most famous kpop group is. The top two from SM are Girls Generation and Super Junior. The top two from YG Entertainment are Big Bang and 2NE1. I listed one girl and one boy group for each.
It was originally founded by Lee Soo Man, hence SM. But now SM stands for Star Museum.
Originally it was an abbreviation of the company founders name, Lee Soo-man, but now stands for "Success Museum".
She is his niece