Anyone who has played Halo may have noticed the lack of option to mute the music. This is no oversight - Bungie's audio director, Marty O'Donnell, refused to work on the game if the option was included. That's despite the fact such an option is on the Microsoft TCR list, a set of requirements to which all games - in theory - must adhere.
Obviously, it's not necessarily a gamble that would pay off for anyone working at a developer other than Microsoft's top first-party studio, but it does give you an insight into just how seriously O'Donnell takes the role of game audio and the lengths he'll go to protect it.
Asked to deliver a keynote at last week's Develop Conference, he urged fellow artists to push the boundaries of their art while he talked about its future.
But first, he spoke of the past and, specifically, what he has learnt since joining this industry in 1996 after a considerable spell in film and TV commercial work. One fundamental lesson is the need for creative exploration to drive technical development. "If we focus so much on the technology, we lose something," O'Donnell argues, saying that while he understands the reason for videogaming to have remained mostly tech-led, there is an opportunity to turn things around by taking more artistic risks when it comes to audio.
"It seems to me that when you're working with engineers, and particularly the kind of engineers who make games, they get so involved in the technology of what they're creating that they somehow think that's good enough. [They think] building the next engine or having the next hardware platform is what it's all about." And in the case of games with strong narrative-driven content such as Halo (indeed, all of his previous game work), O'Connell believes that isn't the audience primary concern. "The audience is interested in just a really great experience."
That, Bungie's audio director suggests, has to start with creativity and actively breaking away from established concepts. "The aesthetic that says that every level needs to have wall-to-wall music is completely ridiculous," he offers as a primary example of something that continues to this day. For O'Donnell, sound effects can have as strong an emotional impact as music and the latter should therefore be used sparingly. "[Designers] think that way out of tradition because that's how they grew up playing games. I just think that as sound designers and musicians we should just kill that forever."
Another concept on the hit list is repetition. "What I've discovered is that repetition is the thing that totally brings people out of the experience - the audio experience, especially," he says, pointing out that you can generally get away with more visual than aural repetition. So fixing this problem has been a particular focus for O'Donnell. Eventually, it came down to developing an engine that randomises sequences of ambient loops and overlays details (such as rhythmic sections) in a manner that the brain accepts as plausible - of course, the various sections have to be musically compatible to begin with, which is where the skill comes in.
This is how Halo 2's soundtrack is constructed, meaning that every time you play it, the action is scored subtly differently. It's also a highly flexible and adaptive system, a crucial facet of trying to establish the mood of the player without ever breaking the spell. O'Donnell explains: "I might know what emotional state I'd like them to be in but I don't know how long they're going to be [in that scene]. So I want to have as many tools as possible to give them an exciting experience but the thing I absolutely don't want to do is make them be aware that they're affecting the music. They can trigger starts, they can trigger alternative things that happen in the middle, they can trigger the way the ending is going to go but if they're aware that they're doing that then they're playing a music game. And I don't want them to play a music game, I want them to play Halo, which is a dramatic story driven game."
This is what O'Donnell considers a creative approach to scoring games. "How many people have worked for designers and engineers who've come up to you and said, 'Here is the way we're going to implement music: we need battle music, we need scary music, we need walking around music'? What good is that? That means it's predictable," he blasts, criticising this method for telegraphing the game's intentions to players and thereby removing all dramatic tension.
So, going forward, it's crucial for audio directors - and Bungie's music man strongly believes every studio should have one - to be in control of these decisions. "We have to be the ones implementing this stuff. We cannot let this be in the hand of the designers and the engineers because they make the wrong decisions," he says, adamantly. "Essentially we need to be game designers with an audio expertise."
But ultimately, there's one aspect that should drive all of the above. "There's nothing more important thing to this business than creativity - not the technical side, not the business side; the most important thing is creativity," O'Donnell reiterates. "And if you've got the creative side, take advantage of it. That's the future."