Guest singers are seated in a waiting room with the three hosts, where they introduce themselves to viewers. The order of performances is decided randomly by presenter Shin Dong-yeop drawing a ball containing the performer's name, and the 500 member audience votes after each round for their favorite performance. The performer with the most votes by the episode wins. Starting February 15, 2020, due to the COVID-19 pandemic, the votes will be made by 20 special judges (mostly KBS employees). They will score the artist however, the score will not be shown and instead a light will shine for the one with the most votes.

In the program where many legendary artists take the stage, the performances are completely live. Idols rarely taketrophy in Immortal Songs. Here are the idol group performances are able to get trophies in the program.

1. B1A4 (Sandeul & Baro) - Ways to Live Like a Man (EP 78)

2. Niel (Teen Top) & 100% - Longing for You (EP 106)

3. ZE:A - Step by Step (EP 148)

4. MAMAMOO - Backwoods (EP 223)

5. MAMAMOO - Wonderful Confession (EP 249)

6. BTOB - To My Love (EP 264)

7. Wanna One - Summer Story (EP 318)

8. Mamamoo - The Dance in Rhythm (EP 333)

9. Seventeen - Short Hair (EP 353)

10. N.Flying - Friend (EP 429)

11. The Rose - City Street (EP 445)

12.Hyun Jin-young with Golden Child - My Dear in My Vague Memories (EP 443)

13. ATEEZ - Black Cat