public function transpose($amount) {
		$func = function($n) use ($amount) {return \ianring\PMTObject::_truemod(($n + $amount), 12);};
		$this->tones = array_map($func, $this->tones);
	}
public function transpose($amount) {
		$func = function($n) use ($amount) {return \ianring\PMTObject::_truemod(($n + $amount), 12);};
		$this->tones = array_map($func, $this->tones);
	}
public function transpose ( $ amount ) { $ func = function ( $ n ) use ( $ amount ) { return \ ianring \ PMTObject :: _truemod ( ( $ n + $ amount ) , 12 ) ; } ; $ this -> tones = array_map ( $ func , $ this -> tones ) ; }
Moves pitch classes up or down by a number of semitones. Positive amount means ascending,
negative amount means descending.
@return [type] [description]
Moves pitch classes up or down by a number of semitones . Positive amount means ascending negative amount means descending .