Code:
alias contplay {
  if !$1 {
    var %a = $rand(1,4)
    if %a == 1 { set %p3dir c:\documents and settings\desktop\skynyrd tunes\ }
    if %a == 2 { set %p3dir c:\documents and settings\desktop\motown\ }
    if %a == 3 { set %p3dir c:\documents and settings\desktop\tunes\ }
    if %a == 4 { set %p3dir c:\documents and settings\desktop\alternative\ }  }
  }
  var %b = $findfile(%p3dir,*.mp3,$r(1,$findfile(%p3dir,*.mp3,0)),run -np $1-)
  msg $active $+(1[,$r(1,7),Continuous-Play1] [,$base($r(1,7),10,10,2),$nopath(%b),1])
  .timersong 1 $calc($mp3(%rand).length / 1000) contplay $calc(($1 + 1) % 10)
}