Ethan Hawke was ''kept up at night'' worrying about his new movie 'Blaze'.

The 47-year-old actor admits he was nervous about directing the drama movie, which follows the story of songwriter Blaze Foley, but is ''really proud'' of how it turned out.

He said: ''I'm really proud of it, but yeah - it kept me up at night. But part of the DNA of the project was to make a music movie that might fail at some things but wouldn't fail at being authentic to the music. All the music is recorded live. You know, I got [Kris] Kristofferson in there, the patron saint of actor-singers or actor-artists; I got Alynda Segarra from Hurray for the Riff Raff to play Blaze's sister.

''I invited Gurf Morlix - who's an amazing singer-songwriter and, along with Townes, was one of Blaze's best friends - to be on set all the time, and he worked with Ben on exactly how Blaze picked that song and exactly what the phrasing and the pacing was of each songs. 'Cause our idea wasn't to fix the songs - we wanted to defend the songs, play them the way that Blaze would have played them.''

And Ethan treated the movie just as a ''workshop'' and was so thrilled that they all ''came through in an incredibly huge way''.

He added to Vogue magazine: ''And having Charlie Sexton play Townes - he's just incredible in the movie. I met Charlie when I was doing 'Boyhood' - and we hung out a bunch, because that movie took years to make, so we got to know each other. And he plays with [Bob] Dylan all the time, and I'd go see him a couple times a year and talk to him - and he's always studying acting. He just loves acting.

''I mean, when you meet a Texan who's been playing rock 'n' roll who likes talking about Daniel Day-Lewis, you just go, Okay - interesting. And Charlie knew Townes. He knew Blaze. He was a little kid in Austin and saw them and hung around with them. He was a vital part of bringing in the right feeling and the right energy and making sure there was no lying in this film. The idea was just to run a little acting workshop for these incredibly talented musicians and just see what happens. And they all came through in incredibly huge ways.''