He was born on September 26, 1928 in Isfahan. His father appreciated music and his home was a popular rendezvous for musicians, among them Seyed Hosein Taherzadeh (vocalist), Akbar Khan Noroozi (tar), Gholamhosein Saranj (kamancheh), Jallil and Hosein Shahnaz (tar), Esmayil Addib Khansari (vocalist), Jaflal Taj Isfahani (vocalist), and Maestro Aboihassan Sabba. Growing up in such a home, Kassai developed a keen sense of musical and vocal appreciation.
His father, having noticed his son's being a music prodigy, asked Taj Isfahani to give him lessons on vocals. In 1947, Maestro Mehdi Navai (a great expert of the nay and one of Nayeb Asdollah's students) agreed to give lessons to the young Kassayi. This tuition period was to last only three months due to the maestro's demise before which he had mentioned to Kassayi's father, "All that I acquired in forty years, this youth learned from me in only three months."
Navai's successor as Kassai's instructor was Maestro Abolhassan Sabba who managed to transfer his unique talent and creativity to Kassayi who in turn took advantage of this opportunity to become acquainted with some of the delicacies of the rich heritage of Iranian music and, thus, achieve the honorable position he holds in music today. Maestro Kassayi has been playing the nay for over fifty years. It is to his credit and a result of his hard work and creative spirit that this instrument has won such recognition nowadays. Many a tune that is played today on the ney would be unthinkable prior to Kassai.
Kassai has 1 CD which is very nice, cleanest recording I've ever heard. Hassan Kassai, "IRAN Hassan Kassai: Le ney", Playa Sound PS65051. There are many bootleg tapes circulating, none official. Recently a double CD with many old recordings of Kassai has appeared: "In Honor of Maestro Hassan Kassayi's 50 Years of Contribution to Music Product of: The Society of The Music of Iran Supervising the production: Mahour Productions".