 		} else if partByte == kPartTypeAcoustic3 {
 			mainType = .Acoustic
 			subType = .Acoustic3
-		} else if partByte == kPartTypeAcoustic4 {
+		} else if partByte == kPartTypeAcousticTWOrgan {
 			mainType = .Acoustic
-			subType = .Acoustic4
+			subType = .AcousticTWOrgan
 		} else if partByte == kPartTypeDrumSet1 {
 			mainType = .DrumSet
 			subType = .DrumSet1

	case Acoustic1
	case Acoustic2
	case Acoustic3
	case Acoustic4
	case DrumSet1
	case DrumSet2
}

private let kPartTypeAcoustic1 = 0x59 // MSB: 89
private let kPartTypeAcoustic2 = 0xD9
private let kPartTypeAcoustic3 = 0xDA
private let kPartTypeAcousticTWOrgan = 0x5C
private let kPartTypeDrumSet1 = 0x56
private let kPartTypeDrumSet2 = 0xD6

