inst_renamer.php

<?php
$notes = explode(" ", "NC NCS ND NDS NE NF NFS NG NGS NA NAS NB");

$inst = "SteelDrum";
$start_octave = 2;

$preview = 1;

$location = "/tmp";

$dir = new DirectoryIterator($location);
foreach ($dir as $fileinfo) {
	if($fileinfo->isDot()) {
		continue;
	}
	if($fileinfo->getExtension() == "wav") {
		$fullname = $fileinfo->getFilename();
		$filename = substr($fullname, 0, stripos($fullname, "."));
		$channel = substr($filename, stripos($filename, "-")+1);

		//str_replace(search, replace, subject)
		$note = str_replace("N", ceil($channel / 12)+($start_octave-1), $notes[($channel-1) % 12]);
		echo "$filename --> {$inst}_{$note}\n";

		if(!$preview) {
			exec("mv $location/$fullname $location/{$inst}_{$note}.wav");
		}
		echo("mv $location/$fullname $location/{$inst}_{$note}.wav\n");
	}
}