Ramin Djawadi has composed the score for HBO's "Game of Thrones" since the very beginning.

For the eighth and final season, Djawadi had to lock himself alone in his studio to watch the new episodes "hundreds of times" before writing the new music.

Though Djawadi wouldn't confirm if we'll hear new instruments, he says there are new themes on the coming episodes.

"I can say there are new themes, definitely," Djawadi told INSIDER during HBO's season eight red carpet premiere.

during HBO's season eight red carpet premiere. Visit INSIDER.com for more stories.

"Game of Thrones" composer Ramin Djawadi has been a central craftsmen of HBO's iconic series since the very first episode. For the coming final season, he's keeping the secrets of the score close to his chest.

"I don't know if I should … or what I can even say at this point," Djawadi told INSIDER at the season eight premiere in New York City last week when asked if there are any new instruments we'll hear on season eight. "I can say there are new themes, definitely, and there are plenty of the existing themes as well, with new iterations."

Djawadi says the experience of producing this final season has been "bittersweet."

"It's obviously super exciting but writing this final season was definitely very emotional for me," Djawadi said. "I went through all the ups and downs all by myself."

He was sent the final season's episodes earlier this year, but had to watch them by himself in order to maintain the secrecy of how the show ends.

"Obviously it's so under wraps that even my direct team can't have access to my studio," Djawadi said. "So it was just me and nobody else, all the doors were locked. It was quite emotional."

Jon Snow (Kit Harington) and Daenerys Targaryen (Emilia Clarke) on "Game of Thrones" season eight. Helen Sloan/HBO

The music you hear on "Game of Thrones" isn't just written by Djawadi; he plays most of the instruments himself and then assembles the individual layers into one cohesive piece for the score.

Djawadi told INSIDER he watched all six episodes "straight through" before he started writing any music.

"Then I re-watched them countless times," Djawadi said. "Like hundreds and hundreds of times."

One theme INSIDER is eager to hear on the coming official soundtrack is the music which plays during Jaime Lannister's signature moments, including the memorable bathtub monologue on season three and when Jaime goes to treat with the Blackfish on season six.

Neither of those pieces of score were put on the official released compilations fans can buy or stream. But Djawadi says he should finally get Jaime's theme onto the released season eight soundtrack.

"Yes, definitely," Djawadi said. "A lot of people have approached me [about that]. It's interesting, when I get stuff ready for the soundtrack I sometimes think, 'Oh this piece is too short,' and then all these people ask why it's not on there."

"I feel like I should go back and look through all the unreleased material and do something with it," Djawadi said.

We suggested he release a bonus soundtrack after the series finale.

"Yeah, I think we have to," Djawadi replied.

"Game of Thrones" premieres Sunday, April 14, at 9 p.m. ET. Tune in to hear if any of those new themes teased by Djawadi makes it into the first episode of season eight.