public static function renderPmn($scale) {
		if (is_integer($scale)) {
			$scale = new Scale($scale);
		}
		$spectrum = $scale->spectrum();
		$string = '';
		// remember these are 0-based, so they're like the number of semitones minus 1
		$classes = array('p' => 4, 'm' => 3, 'n' => 2, 's' => 1, 'd' => 0, 't' => 5);
		foreach ($classes as $class => $interval) {
			if ($spectrum[$interval] > 0) {
				$string .= $class;
			}
			if ($spectrum[$interval] > 1) {
				$string .= '<sup>'.$spectrum[$interval].'</sup>';
			}
		}
		return '<em>' . $string . '</em>';
	}