Maria Sensi Sellner and violist Jason Hohn fill us in on "In Excelsis," the concerts Thursday February 9th and Saturday February 11th at the Third Presbyterian Church with an American premiere of "Gloria" by James Macmillan along with his "Cecilia Virgo" and "Seraph," Neal Berntsen of the Pittsburgh Symphony playing the  "Prayer of St Gregory" by Allen Hovhaness, Verdi’s "Ave Maria" and "Flos Campi" by Vaughan Williams. Russell Weismann plays the organ, while the Festival Chorus and Pittsburgh  Youth Chorus sing. Topics include what it was like working with the composer at rehearsal.