 Included in the series are Messiaen's major compositions such as "Catalogue d'oiseaux", "Vingt regards sur l'enfant-Jésus", and the two-piano work "Visions de l'Amen" recorded with his son, Matthew Kim, who was 15 years old at that time.Critics have noted Kim's interpretations with references to his scholarly perspectives, athletic and poetic pianism, and spiritual qualities.The pianist Yvonne Loriod, the late composer's wife and the foremost interpreter of his music, described Kim's performances as "perfect in every way — technique, rhythm, color, sonority, emotion."