MBLAQ has kicked off their follow-up with "I Don't Know" on this week's episode of 'M! Countdown'! "I Don't Know" was made by the composers of "Mona Lisa" and tells the story about a guy who doesn't understand a girl's heart and mind.�The song is particularly favored for its witty lyrics and easy-to-follow melody, and is already expected to become a hit. MBLAQ's leader Seungho stated, "Every time people ask what the follow-up song for 'Mona Lisa' is, we say 'I Don't Know' and they look at us oddly. 'I Don't Know' is a song which battled 'Mona Lisa' until the end for the title song position. You can experience a different MBLAQ charm with this song." Check out their new performance below! Source + Image: mydaily via Nate Tip: Happy