The Glee star told Access Hollywood Live hosts Billy Bush and Kit Hoover that collaborating with the legendary 'Candle In The Wind' singer was one of the most electrifying experiences of his life.
"I was actually just listening to that track we did today… it's an epic song," he said.
The star continued: "It's [a cover of John's] 'Mona Lisas and Madhatters' and it kind of goes into 'Rocket Man', and I was listening to it, and just hearing Elton John's voice, and his voice fades out and my voice comes in, and I'm like, 'What world am I living in right now?' It's just, like, crazy."
Morrison further explained that the LP's first single 'Summer Rain' was inspired by a particularly fond moment with an former lover.
"It's kind of about making love on a roof," he remarked. "I wanted to capture a moment in time that I had with an ex-girlfriend of mine. It was such a beautiful moment - it was about being young and in New York."
"It was something when I'm 65 I'm going to look back on and be like, 'That was an awesome moment'. It's one of those memory burns you have and I really wanted to make a song out of it. It was actually the first song I wrote on the album."
The singer, who has scored two US platinum-selling albums with his Glee castmates, is to release his self-titled solo record in May.