Adam Lambert ''didn't believe'' he could be a songwriter.

The 37-year-old singer shot to fame when he competed on 'American Idol' in 2009, but admitted that with his background being in musical theatre, he didn't think he had any chance of becoming a chart star, so credits his friend Alisan Porter - who won 'The Voice' in 2016 - for encouraging him to follow his dreams.

He said: ''Alisan won 'The Voice' and was a child actress so she's been in the business for a long time and I respect her a lot.

''She's a songwriter and a mother-of-two, and very independent, which I really admire.

''We were in a musical together and became good friends.

''Alisan encouraged me to write a song aged 23 - it was the first time I'd ever done that.

''I didn't believe I could become a songwriter and a recording artist because if you come from musical theatre, people make assumptions about the type of artist you are.

''Alisan is one of the reasons I made it.''

Adam also praised his mother Leila for always being his biggest fan.

He told Marie Claire magazine: ''Mom has always given me unwavering love and support.

''As a teenager, she became more than just a mom to me. She was my friend and we were really close.

''I remember going on a trip together to New York when I was 14 and we laughed a lot.

''She's always been my number one, telling me I'd make it before I really believed it.''

Though the 'Ghost Town' singer admitted his life ''changed a great deal'' after he found fame, he vowed never to move on from his loyal friends.

Speaking about his pal Danielle Stori, he said: ''We grew up down the street from one another and Danielle is like my sister.

''When the 'Idol' thing happened, she said, 'I feel like I'm gonna lose you now.' I remember saying, 'That will never happen.'

''My life changed a great deal but I was 27 and knew the people I loved weren't going anywhere.

''I respect Danielle a great deal. She's hugely inspirational to me.''