Leibeleh was a great musician, he had a vast knowledge of composition and counterpoint. He could have made his vocation as a professor in the largest Music Academy had he chosen to do so.
He analyzed every prayer and compared it with the traditions and made far reaching changes to many melodies anchored wrongly in the common practice of Chazonim.
I asked once the late Chazan Israel Alter (known authority on Nussach and composer of the "Akavio Ben Mahalalel" made famous by Moishe Koussevitzky), on his opinion about Leibeleh Glantz's approach to Chazonus and he told me: "I like his questions, but not always his solutions" !
Besides being such a musician, Leibeleh Glantz had an unusualy high and flexible Tenor voice. When one was listening to him, one had the impression that his vocal possibilities were limitless.
Leibeleh Glantz introduced new modes in his compositions, which had a lot in common with the expressionism trend in paintings. He was all for expressiveness.
Many people from the masses of Chazonus lovers, did not understand his ways. But there are many for whom Leibeleh Glantz is the ideal interpretor of Chazonus.
Leibeleh Glantz was also an extremely gifted composer. His “Shema YisroeL” sung in the Mussaf service of Shabbath and Holidays, is considered a jewel of Chazonus compositions.
My good friend Akiva Zimmerman, a world known authority on Chazonim and Chazonus, used to go regularly to listen to Leibeleh Glantz in the Synagogue. He told me, that the listeners were fascinated when he started to plainly speak the words of the prayers without any melody. It sounded like he was talking to Hashem Almighty.