Idina Menzel says 'Let It Go' was ''lightning in a bottle''.

The 'Frozen' actress belted out the modern Disney classic in the 2013 animated favourite and although she acknowledged how difficult it is to replicate something so special, she thinks the sequel's songs can hold their own in a different way.

Menzel - who will reprise her role as Elsa in the upcoming movie - told The Hollywood Reporter: '''Into the Unknown', and then there's another song called 'Show Yourself', which is pretty spectacular as well.

''Everyone always asks is it the next 'Let it Go'? That's lightning in a bottle. All I know is this [new] music really moved me when I heard it, and it moved me more when I was interpreting it.''

The 48-year-old star insisted while 'Let It Go' annoys a lot of parents, the track has given her a special connection with younger fans all around the world while also pushing her to embrace the empowering lyrics.

She said: '''Let It Go' - as much as it might be annoying to a lot of mums out there, and dads - it's one of the great gifts of my career.

''It's given me a way of communicating and connecting with young people that brings me so much joy. And also, it's a reminder to a woman in her 40s who has to be a role model to young people to practice what you preach.''

Meanwhile, Menzel previously revealed despite its huge popularity her son Walker, 10, isn't a fan of the first film and thinks 'Let It Go' is a ''stupid song''.

Speaking in 2017, she said: ''He's seen it maybe twice, he hates it. It's princessy and it's mommy singing so it means that she has to work and go sing the stupid song, and it takes me away from him.''