As art director of "Art & Artists Magazine", he met The Beatles towards the end of the 1960s and was hired as Creative Director for Apple Records, where he was responsible for design, promotion and publicity. During this period he designed albums for a clientele that covered numerous British rock bands including The Rolling Stones. In 1969 Kosh handled the "War Is Over" campaign for John Lennon and Yoko Ono and created the famous "Abbey Road" and "Who's Next" album covers. During this period Kosh became well known in the London avant-garde art scene for designing and producing exhibitions, posters and books.