Just about every Sunday at 3pm from April to October there are free traditional Korean music and dance performances at a facility called Seoul Nori Madang. The facility is a roofed outdoor amphitheater with a few hundred seats around a large circular performance floor. Anyone is welcome and there are even floor spaces for people in wheel chairs. Bathrooms are only a minute away from the back entrance of the amphitheater.
I found no updated/accurate information on the internet about getting there, but it's easy enough for me to explain. Jamsil Station on subway line #2 (green line) is where you need to head. Once there, come out of the station at exit #3 and head around the department store to the back. Turn right and walk until you see the amphitheater on your left. Cross the street and you are now on the edge of Seokchon Lake Park and at the entrance to the amphitheater. Use this google map of the area for help.
The performances usually last 1 to 1.5 hours, but on my last visit the performances lasted 2.5 hours. The performances are mostly traditional; however you will see some "fusion" performances that have a mix of traditional and modern art. It's hard to know what you're going to see when you're there because all of the performance information is in Korean. But don't let that stop you from going, because it's always a good time. Also, showing up 30 minutes before show time will almost guarantee you a front row seat.
Sitting at my desk and looking back at the many times I have gone to the Seoul Nori Madang, I can easily recommend this activity to you. It is on my list of ‘must do things' in Seoul for any of my friends that visit. I can't recommend it enough for lovers of traditional music and dance performances.
The Seoul Nori Madang isn't the only place one can see live performaces of traditional Korean music. There are also the Chongdong Theater (tickets), the Korea House (tickets), and the Seoul Pungnyu Hanmadang (free).
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