public void setVolume(String sourcename, float value) {
		if (midiSourcename(sourcename)) {
			midiChannel.setVolume(value);
		} else {
			Source mySource = sourceMap.get(sourcename);
			if (mySource != null) {
				float newVolume = value;
				if (newVolume < 0.0f)
					newVolume = 0.0f;
				else if (newVolume > 1.0f)
					newVolume = 1.0f;

				mySource.sourceVolume = newVolume;
				mySource.positionChanged();
			}
		}
	}