"Halfcrazy" is the lead single from Musiq Soulchild's second album Juslisen. It was released as a 12" single on February 26, 2002. "Halfcrazy" contains an interpolation of the Charlie Byrd song "Vivre Pour Vivre", a cover of the Francis Lai composition. It is considered as Musiq Soulchild's signature song.
"Halfcrazy" debuted on the BillboardHot R&B/Hip-Hop Songs chart on February 23, 2002, and peaked at number two in a 42 week stay on the chart. It entered the Billboard Hot 100 on March 23, 2002, peaking at number 16 in a 25 week chart run. It is the biggest pop hit of Musiq Soulchild's career.