During 2AM's Christmas concert, 2AM expressed their regret over a few songs that originally belonged to them. On December 24th, 2AM sang an acoustic medley of songs including K.Will's "Left Chest", 2PM's "Only You",  Taecyeon and Nichkhun's "My Valentine", and J.Y. Park's "If" from the 'Dream High' OST. All four of these songs were songs that were so close to being 2AM songs. 2AM explained,

"Actually, K.Will's debut song 'Left Chest' was planned to be our debut song. But producer J.Y. Park, who made the song, kicked us out of the recording studio because our singing was so poor at the time. [As for 'My Valentine'] we feel that it was unfair. Apparently, being brothers doesn't matter when it comes to a good song. 'My Valentine' was suppose to be a single that we were going to release on Valentine's Day and 'Only You' was suppose to be included in our album. [As for 'If'] This song was a song that almost became our title track. This song was going to be the song that we sang instead of 'Confession of a Friend' for our 2nd album. We even recorded the song and took jacket photos, but even at this time, we were not good enough singers so our title song changed for that reason. We asked him (J.Y. Park) for the song for several years but he said he gave it to a different singer. As it turns out, it was he who sang the song himself. So whenever we watched 'Dream High' and this song came on, we used to just change the channel."