Complex sentence: On June 7,2007 the group performed their debut song, "Love Sick" on the music television program, "M Countdown" and their debut album, "Cheerful Sensibility" was released on the same day.
Split into simpler sentences: On June 7,2007 the group performed their debut song "Love Sick" on the music television program M! Countdown; their debut album, "Cheerful Sensibility," was released on the same day.