If crazy denotes an anagram and the singer is (Helen) Reddy, that could be rearranged to 'ddery' which leads me to think it could be Pat (or Paul) Eddery.
However I can't solve the rest if that is so....Singular is usually a 'bits and pieces' indicator for 'S' in cryptic clues....and as for the footballer Colin, Todd immediately sprung to mind although obviously there's lots of other options....