By BBC News Online's Alfred Hermida

Music worthy of Hollywood blockbuster films is breaking into the fantasy world of video games.

The game designers of the forthcoming title Metal Gear Solid 2 felt the game's cinematic visuals and strong storyline deserved music of which any Hollywood producer would be proud.

So they approached British film composer Harry Gregson-Williams, whose credits include the animated film Shrek, the thriller Spy Game and the disaster movie Armageddon.

"They wanted it to sound like a film score and not like a cheap video game," Mr Gregson-Williams told the BBC programme Go Digital. "It was very rewarding,"

Lush soundscapes

As computer graphics get more realistic and sophisticated, game designers are paying more attention to how music can help set up emotional scenes.

Ryan: Digital opportunities for composers

At the same time, digital technology has opened up new possibilities for composers.

"Whereas before the technology was inhibiting the music for computer games, it is now actually opening a whole range of possibilities," said composer and sound designer Nick Ryan.

"You can now create an incredible range of lush sound," said Mr Ryan, who wrote a track for the Playstation 2 futuristic racing game Wipeout Fusion.

Fragmented music

But writing for an interactive game places its own particular demands on a composer.

Wipeout Fusion: Fast-paced racing game

"You can't predetermine where a character is going to be in a game so you can't write a piece of music that starts at A and ends at B," explained the composer Nick Ryan.

"We need to write bits of music that blend into one another and have different emotional resonances.

"We break down the music into small fragments that can be pieced together by the actual game software as you play it."

Creative freedom

This is what Mr Gregson-Williams found when he was asked to write the score for Metal Gear Solid 2: Sons of Liberty.

He was asked by the game's designer, Hideo Kojima, to write a series of music modules, reflecting the different circumstances in which the main character in this action adventure would find himself.

Gregson-Williams: First soundtrack for a game

"The whole appeal of it to me was that in my film-composing career, I have to compose music to the pictures. The music is dictated by the pictures," explained Mr Gregson-Williams.

"In this instance, I composed the music without the game, so there was a certain liberty there.

"I was able to compose lots of music which they then fitted into the game," said the classically trained composer.

"With a film score, I always know how the music is going to end up," he said. "With this, I had to write the music in advance and I was never quite sure how the music was going to work with the pictures."

Metal Gear Solid 2: Sons of Liberty for the Playstation 2 is out in the UK on 8 March. Wipeout Fusion for the Playstation 2 is out now.