"Yesterday I was at a concert dedicated to Korean holiday 설날."
=> 어제는 설날 특별 공연에 갔었어 / 어젠 설날 (기념) 콘서트에 갔더랬어.
- ~에 갔었어: was there/ have been there. (~었어 is similar to past perfect or present perfect).
- 갔더랬어: ~더랬어 is like "I did, you know", a colloquial form relating an experience (hard to translate).
- dedicated to XX: XX 헌정 공연, XX 기념 공연, or juts XX 공연.
* 헌정: tribute; XX에 헌정하다: dedicate smth to XX; 허정 공연: tribute concert.
* 기념: commemoration; XX를 기념하다: commemorate XX; 기념식: commemoration ceremony.
* For 설날 which comes around every year, 헌정 or 기념 seems too formal - "설날 (특별) 공연" is more natural.