Its most popular song, "Hawaiian Couple", a top ten hit[5] that reportedly sold over 500 000 downloads, came from the band's second album, Purple Drop, released in March 2006.
[6] Hawaiian Couple was also featured in the film My Love, a popular 2007 South Korean romantic comedy, directed by Lee Han.
In March 2012, the main female vocal "Humming Girl" Lee Jin-hwa died in Japan.
Lee Jin-hwa flew to Japan to study abroad in 2007 after singing for Humming Urban Stereo, and had been living alone since for six or seven years.
For the band's 10th anniversary, they released the album "Reform," covering old hits such as 'Scully Doesn't Know', 'Insomnia', 'Bullshit', 'Salad Day' and their biggest hit 'Hawaiian Couple' having guest vocals from mainstream artists such as G.Na, NS Yoon G, Narsha of Brown Eyed Girls, and Ashley of Ladies' Code.