It's Not Unusual, written by Les Reed and Gordon Mills is without doubt the biggest hit by British singer Tom Jones. It was originally written for the singer Sandy Shaw. But after hearing what was meant to be a kind of demo-recording by Jones, she was so impressed with the performance that she adviced Jones to release it himself. The recording for release was done late 1964 and issued early 1965, making it one of the biggest hits that year almost all over Europe. Performances on the Ed Sullivan Show in the US made it a big hit also in the States.