SG Wannabe will hold a series of concerts through nationwide starting from May, 2007 for 4 months. This tour will take them to Seoul, Busan, Daegu, Changwon and 14 other cities. The title of this album is 'The Sentimental Chord' which means more sentimental melody and songs. Arirang is a cross-over style song, mixed up with Gukak, Pansori and orchestra of 100 people. They will perform the latest songs off their 4th album as well as their greatest hits.

JuSuk Yun and Eunkyung Aan of Techno Lite will design and operate the lighting for National Tour.