The crossword solution for the term 'CLASSICAL GAS' is ESSO, a four letter word. ESSO is an international oil and GAS company that was founded in 1912 in the United States. It is now a subsidiary of the multinational energy corporation, ExxonMobil. The term 'CLASSICAL GAS' is a 1968 instrumental composition by American guitarist and composer Mason Williams. It has been covered by many artists and is considered a classic in the genre of instrumental rock music.