If a xs:choice is nested in a xs:sequence running the generated code throws an exception like:
Type of choice identifier 'Items1ElementName' is inconsistent with type of 'Items1'. Please use array of System.Collections.Generic.List ...
This error was raised and described in http://xsd2code.codeplex.com/discussions/48138 and http://xsd2code.codeplex.com/discussions/224616 but no real solution was provided in any of the discussion threads as replacing the List by an array causes another error (at least in NET 4): Unable to generate a temporary class (result=1). error CS1061: 'System.Collections.Generic.List<namespace.FlexPropType>' does not contain a definition for 'Length' and no extension method 'Length' accepting a first argument of type 'System.Collections.Generic.List<namespace.FlexPropType>' could be found (are you missing a using directive or an assembly reference?) (this error is described at http://stackoverflow.com/questions/6866301)
 
So maybe a modification in the Xsd2Code code template could solve this issue.

        try {

            Note n = new Note() {
                Type = new Notetype() {
                    Value = Notetypevalue.whole
                }
            };

            n.ItemsElementName.Add(ItemsChoiceType1.pitch);
            n.Items.Add(new Pitch() {
                Step = Step.A,
                Octave = "4"
            });

            n.ItemsElementName.Add(ItemsChoiceType1.duration);
            n.Items.Add("4");

            Debug.WriteLine(n.Serialize());

        } catch (Exception) {

            throw;
        }