On Thursday, February 27, at 7:30 p.m., the early music vocal ensemble Blue Heron will present a concert in the First Parish Sanctuary.

The subject of the program is Ars subtilior, or “A more subtle art.” This late-14th-century singing style is characterized by rhythmic and notational complexity. Learn more from Wikipedia.

A member of the ensemble is tenor Jason McStoots, who was a featured soloist in many First Parish Music Sundays in past years.

The harp illustration is an example of the ornate written music associated with the style.