Ustad Ghulam Haider Khan is a classical vocalist of repute. Son of famous clarinet player Ustad Mando Khan, he has also written many books on music, the latest being 32 Thaath Ka Nizam-e-Mausiqi. All his life he has remained in a lookout for new innovations in the domain of classical music and written six books as per my knowledge; Naghmat-e-Khusrau, Kehet Sada Rang, 100 Achob Raag, Tazkia-e-Mausiqi, Qasur Gharana Ke Namwer Fankaar, Music of Radio Pakistan etc. Ustad Ghulam Haider holds regular musical functions under his organisation, Pakistan Classical Music Guild. This book under review is based on his research work. One of the reasons for this research was that Indian musicologists named Aimen Thaath as Kalyan Thaath and because of similar other anomalies. According to the writer, the name Aimen Thaath was first given by Lochin in 1000. After 600 years Ahopal named it Kalyan Thaath. Venkat Mukhi and Bharat Khande followed suit. Actually the word Aimen belongs to the Arabs which means all is well. In Hindi language the word Kalyan had similar connotations. A peace loving God in Firaena era had the same name. Hunood followers were envious of Muslims since the beginning. They changed the name of Aimen Thaath to Kalyan Thaath. Similarly Sultan Hussain Sharqi’s innovation Jonpuri’s name was changed as Asaawari Thaath. Ustad Ghulam Haider further states that even Hindu critics have admitted that the inventors of the scales of Marwa and Todi Thaaths have been Muslim innovators. Moreover the centuries old music of India’s book Saam Ved’s Ashlok were based on five notes as the concept of seven and twelve notes did not exist then. When Muslims entered India in the 12th and 13th centuries, they brought books on music in Farsi and Turk languages that were translated and Hindu and Muslims amalgamated and developed a mixed culture of music. Musicologist VN Bhaat admits on page 66 of 1957 version of his book Bhaat Khande Sangeet Shaster that their musicologists were never confident about their created Raags Bhairon, Hindol, Shri and Malkauns. Today these are different raags, so why do not they admit that real musicologists were Muslims? The book under review therefore tracks the history of various thaaths in their true perspective. The thaath system was introduced by Safdar Hussain’s ‘Qanoon Saaz’ and travelled with Muhammad Raza’s ‘Naghmaat-e-Aasifia’. All classical vocalists and instrumentalists rendered raags under this system. The author wrote a book 100 Achob Raag and discussed 32 thaaths and introduced some new thaaths, the reason being that many raags introduced in the 20th century could not be accommodated in 10 thaaths. The author claims to have introduced 22 more thaaths to make its number 32. According to Ustad Ghulam Haider Khan, Bhaat Khande has made his life easy by ignoring many riddles and suppositions and has tried to provide ease to the followers of music. He rejected the existence of 72 Thaath System, advising not to us Shurtis and also negating Garam System of music. Ghulam Haider has stuck to the additional 22 Thaaths apart from the 10 existing ones as per the system followed in the Southern India. He argues that by doing so, the concept of 72 Thaaths dies its own death. From the above terminologies, even as a practicing classical singer, this reviewer finds some names and the groupings new. It shall take a long time to digest these names by the established practitioners. It is for them to amalgamate their knowledge in the proposed Thaaths by Ustad Ghulam Haider Khan’s commendable work.