That chief executive is Steve Jobs, and I know why that speech makes an impact. To a casual observer it is just a guy in a black shirt and jeans talking about some new technology products. But it is in fact an incredibly complex and sophisticated blend of sales pitch, product demonstration and corporate cheerleading, with a dash of religious revival thrown in for good measure. It represents weeks of work, precise orchestration and intense pressure for the scores of people who collectively make up the "man behind the curtain". I know, because I've been there, first as part of the preparation team and later on stage with Steve.

Objectively, Apple Computer is a mid-sized company with a tiny share of its primary market. Apple Macintoshes are only rarely seen in corporate environments, and most software companies don't even offer Apple-compatible versions of their products. To put it another way, Apple is just bit larger than Cadbury-Schweppes and about the same size as Nike or Marks and Spencer in terms of annual sales.

Such comparisons come up short in trying to describe Apple's place in the world of business, because they leave out a key factor: Steve Jobs. That's something only one other company - the filmmaker Pixar - can claim. He's the closest thing to a rock star you will find in the world of business.

When Apple announces something new, people pay attention. This is due, in large measure, to Steve and the way he delivers Apple's messages. His preferred method of making major product announcements is at one of his public presentations, or "keynotes" as they are called inside the company.

Steve starts his preparation for a keynote weeks in advance, reviewing all the products and technologies he might include. Although development and release schedules are set far in advance, he still has to satisfy himself that the chosen products are keynote-ready. For software, this can be hard to decide: the engineering work is usually still underway, so he will make a preliminary determination based on seeing unfinished software. More than once this has caused some tense moments in rehearsal when programs haven't behaved.

Baptism of fire

My first experience of this preparation came in the runup to the Macworld Expo keynote of January 2001, which was to include new Macs able to burn DVDs - then an amazing capability. Steve wanted to show off the new software, iDVD, that could do it. As I was the product manager for Apple's DVD software, I had to organise everything that Steve would need.

The team and I spent hundreds of hours preparing for a segment that lasted about five minutes. Several weeks earlier Steve summoned me to demo the software, and highlight what I thought were its most interesting aspects. Of course he already knew most of this, but the process was still useful. He used the key points from these demos to mould his overall presentation and decide how much time each product would get.

Next, my team was given the task of locating movies, photos and music to be used when he created his sample DVD on stage. Most companies would just choose some clip art, or hire a video producer to make some simulated "home movies". Steve wanted material that looked great, yet was possible for an average person to achieve. So we called on everyone we knew at Apple to submit their best home movies and snapshots. Before long we had an amazing collection of fun, cool and heartwarming videos and photos. My team picked the best and confidently presented them to Steve. True to his reputation as a perfectionist, he hated most of them. We repeated that process several times. At the time I thought he was being unreasonable; but I had to admit that the material we ended up with was much better than what we had begun with.

Then came the process of the demo itself: what precise steps Steve should follow, whether the program should already be running on the computer, what sample movies to play, everything.

With the demo set, my role was to stand by in case of technical problems with the software, or if Steve wanted to change anything. This gave me the opportunity to observe what was going on around me. The big keynotes require a very large crew with separate teams for each major task. One prepares the room to seat several thousand people. Another group builds the stage with its motorised pedestals, risers, trap doors, and so forth. A third manages the stage lighting, audio and effects.

Yet another sets up and calibrates the state-of-the-art projection systems (complete with redundant backup systems), and a huge remote video truck parked outside has its own crew handling video feeds for the webcasts and playback of any video needed during the show. Then there are the people who set up all the computers used in the keynote, each with at least one backup that can be instantly brought online with the flick of a switch.

And of course there's the secrecy. The impact of Steve's presentations depends on surprise; so once the rehearsals begin, security people help keep the curious out and the secrets secret. It was fascinating to watch. No detail was overlooked: for example, while rehearsing the iDVD demo, Steve found that the DVD player's remote control didn't work from where he wanted to stand on the stage. The crew had to make a special repeater system to make it work.

So when Steve steps out on that stage, with its stark black-on-black colour scheme, and does his apparently simple demos, he brings the combined energy and talent of all those people and many more back in Cupertino, California, and channels it to the audience. It makes me think of a magnifying glass used to focus the power of the sun on one small spot until it bursts into flames.

Fast forward a year; much to my surprise I was asked to do a demo in the keynote. And then I really learned about demos. In mid-2001 I had been promoted to manage both the DVD products and Apple's professional video-editing software, Final Cut Pro, a new version of which was to be released in early 2002.

But Steve never does the demos of the pro software; he always relies on someone on the product team more familiar with its features and operation. The job fell to me. It turned out to be my lowest and highest point at Apple.

Steve usually rehearses on the two days before a keynote. On the first day he works on the segments he feels need the most attention. The product managers and engineering managers for each new product are in the room, waiting for their turn. This group also forms Steve's impromptu test audience: he'll often ask for their feedback. He spends a lot of time on his slides, personally writing and designing much of the content, with a little help from Apple's design team.

As each segment of the show is refined, Steve and his producer edit the slides live on a PowerBook so the revised slides can be used immediately. That day Steve was very methodical, going through every aspect of the show. He would test variations of content and flow, looking for the combinations with the most impact. When introducing a major new product, he also liked to show the TV commercial Apple would be using to promote it. Often these had been finished just minutes before rehearsals; Steve would sometimes preview alternate versions to gauge the team's reaction before deciding which to use.

Crunch time

On the day before showtime, things get much more structured, with at least one and sometimes two complete dress rehearsals. Any non-Apple presenters in the keynote take part on the second day (although they cannot be in the room while the secret parts - the unveiling of hot ticket hardware such as a new iPod or laptop - are being rehearsed.) Throughout it all Steve is extremely focused. While we were in that room, all his energy was directed at making this keynote the perfect embodiment of Apple's messages. Steve doesn't give up much of his personality even in rehearsals. He is strictly business, most of the time.

I had worked on my five-minute Final Cut Pro demo for weeks, selecting just the right sample material and honing (I thought) my delivery to a fine edge. My boss and his boss were there for moral support. Steve, as was his custom, sat in the audience. I was very nervous, and having Steve's laser-like attention concentrated on me didn't help. About a minute into the demo, Steve stopped me, saying impatiently, "you gotta get this together or we're going to have to pull this demo from the keynote."

I was devastated. I didn't even know how to respond, or if I should respond. Mercifully my boss and Phil Schiller (Apple's head of marketing, and a frequent keynote presenter) came to my rescue. Over the next few hours they worked with me to polish my demo. More importantly, Phil gave me some great advice: "Those 6,000 Mac fans out there in the hall aren't against you, they're the best friends you can have." The next day at final rehearsal, Steve watched me again. This time he gave it his nod of approval. It felt great; but the real work was yet to be done.

Next morning, as I sat in the front row waiting for my turn on the stage, the full weight of the event hit me. There were several thousand people in the room, and approximately 50,000 watching the webcast. It was the very definition of pressure. Steve started the segment that preceded mine, and my heart started pounding. I felt those hundred thousand eyes all about to be focused on me and feared I would crumble. I had done a bit of public speaking before, but nothing like this.

The assistant producer came over to me to guide me to the stairs at the side of the stage. I stood in the dark, watching Steve put up the slide that introduced me. Just then a wonderful thought hit me; in five minutes the whole thing would be over. If I could only keep going for five minutes I would be fine. I bounced up the stairs and on to the stage, and everything was suddenly OK. The demo worked perfectly, the audience seemed to love the product, and their applause was an incredible adrenaline rush.

When it was over I received many compliments on how well it went, including the one I prize the most, from Steve himself.

In the following months I was on stage for two more keynotes, and each time was incredibly grateful for the apparently harsh treatment Steve had dished out the first time. He forced me to work harder, and in the end I did a much better job than I would have otherwise. I believe it is one of the most important aspects of Steve Jobs's impact on Apple: he has little or no patience for anything but excellence from himself or others.

· Mike Evangelist left Apple in 2002 and is writing a book about his time there, provisionally called Jobs I've Known, live on his site, www.writersblocklive.com

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