Heartless - Heart song - was created in 1978.
Heartless - Kanye West song - was created on 2009-09-14.
Nobodies are like alternate people created when someone with a strong heart is turned into a Heartless. For example, when Sora was turned into a heartless, Roxas was created, because Sora's heart was strong.
The Song of the Heart was created in 2006.
Sora did himself. When Kairi's heart left her body, because it had no darkness considering she was a Princess of Heart, instead of becoming a Heartless her heart entered Sora's heart. In order to release her heart Sora stabbed himself with the Keyblade of People's Hearts, a Keyblade created out of the hearts of the Princesses of Heart by Xehanort's Heartless, releasing Kairi's heart back into her body. However, it also released Sora's heart, which became a Heartless, so he did it to himself to save Kairi.
Heart to Heart - song - was created on 2011-09-07.
Foolish Heart - song - was created in 1984.
In My Heart - Texas song - was created in 1991.
Secret - Heart song - was created in 1990.
Kick It Out - Heart song - was created in 1977.
With a Heart in My Song was created on -19-06-05.
A Song In My Heart was created on 2011-03-21.
My Foolish Heart - song - was created in 1949.