/// <summary>
/// Used by Clone.
/// </summary>
public Grp(Gamut gamut, int midiChannel, int msPositionReContainer, List<IUniqueDef> clonedIUDs)
: base(midiChannel, msPositionReContainer, clonedIUDs)
{
Debug.Assert(gamut != null && gamut.ContainsAllPitches(clonedIUDs));
_gamut = gamut;
SetBeamEnd();
}