form

<xs:attribute name="form">
  <xs:annotation>
    <xs:documentation>Specifies whether enharmonic (written) values or implicit ("perform-able") values are allowed.</xs:documentation>
  </xs:annotation>
  <xs:simpleType>
    <xs:restriction base="xs:token">
      <xs:enumeration value="implicit">
        <xs:annotation>
          <xs:documentation>Only performed values (sharp, flat, natural) allowed.</xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value="explicit">
        <xs:annotation>
          <xs:documentation>All enharmonic (written) values allowed.</xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>