The vocal presentation of Khan Saheb continued from the forties till the end of his life, for about 45 years. Due to influences of guru like senior artists, his own experimentations and age, it was but natural that some changes had to occur into his gayaki.
In the initial years i.e. till 1945, his presentations were full of vitality, keeping pace with fast movement. He emphasized more on tans. At that time, the speed of tans was spectacular. It was the climax of influence of Ustad Rajab Ali Khan. Thereafter comes the period of his ‘rasvad’ [emotionalism]; when improvisation part of Abdul Wahid Khan and the capability to hypnotize by means of swara, gave new dimension to the vocalism of Khan Saheb. During this period because of having good health and vigor, Ustad Amir Khan gave high quality presentation by application of ati vilambit movement of raga, and by ati drut tan and sargam in drut part. This period could be reckoned between 1948 and 1960. This was the climax of his vocalism, whose glimpse can be had from three minutes 78 RPM records and available audio recordings of some programs.
The onward period, after 1960, was affected by old age and disease. Hence, his vocalism continued with certain changes due to circumstances. He comparatively increased the laya of vilambit khayal and adopted the style of presenting tans with less speed and in pieces.
During these days, pain in his liver and stone caused obstacles in his performance; and his voice used to get lax because of cough. During this period, success of his performance depended on his self confidence, contemplation and imagination full of aesthetic sense. The popularity of his LP records made after 1960 and his success in music conferences prove this. The contemplation gave him strength. In later days, the importance of contemplation was more than that of riyaz [practice]. In this context, a part of interview written by Ravindra Visht is as follows: - “IN the last days, Khan Saheb had become weak. The disease of stone had become chronic. He said ‘I have become empty. Though I practice, it does not show so much effect. As I keep contemplating about singing; through whose force I could sing - - -.’ I said: ‘Khan Saheb! Why do you think so about yourself that you have become empty? Every thing will be all right.’ It is a coincidence that he died not by any disease, but by a car accident. Neither he suffered, nor gave trouble. He sang on the stage until his last breath.”
 ‘Sangeet’-January/February 1980, P.19, ‘Meri Gayaki Meri Avaz Hai’, Writer: Ravindra Visht.