During the live broadcast, one fan commented directly at Xiumin, "Didn't you say that you will sing Emerald Castle's 'Footsteps' on live broadcast one day?"

Xiumin explained, "['Footsteps'] is a very special song to me. I made it through SM's audition by singing this song." Then, as promised, Xiumin belting out the rock ballad live for his fans. 

SEE ALSO: Xiumin opens Asia tour with first solo fan concert in Seoul

After Xiumin finished singing, Chen praised him, "I think this is the first time I've seen you sing this song. You sang so well." 

Xiumin gave his reason on choosing this particular song for his audition, saying, "I believed that this song would play best to my strengths. The vibrant high notes fit [my singing style] really well." 

Watch Xiumin's performance for yourself above!