He toured America, South Africa, Australia and New Zealand on several occasions and made a large number of recordings, some of which are available on CD re-issues.
Hislop is notable for having been the final teacher of the Swedish tenor Jussi Björling and for developing a number of fine British singers through his post-War work at the Guildhall School of Music and at Sadler's Wells.
After retiring to Fife, he taught the Scottish baritone Donald Maxwell.