Running on towards three hours, the shows made extensive inroads into Wonder's copious catalogue. The closing flourish was a sequence of hits banged end to end, with barely a pause between them: "Signed Sealed Delivered", "Sir Duke", "I Wish", "Superstition", "You Are the Sunshine of My Life". It unseated the auditorium.
Our familiarity with the material gives Wonder his licence to shuffle it before our ears, to sink himself in the songs and reinvestigate them, finding new paths for his voice to take through the melody lines. There is no other pop performer whose back catalogue is kept this fresh by live performance. In everything he sings, no matter how old, or how frequently exposed, from "Love's in Need of Love Today" to "I Just Called to Say I Love You", he is right inside the song, shaking it awake.
There's a basic set list, a song-order for the show, but you'll notice Wonder leaning back and tossing his head at the ends of some numbers, a sign to the band that he's about to break out of the pattern. It's clearly important to him that the show is flexible enough to respond to his musical whims, which are many and various. During Tuesday's show, for instance, at the close of "Superstition", it seemed to become apparent to him that the song he really wanted to be singing was "Do I Do". So, a nod, a shout, a flurry of activity in the band, and off they went. On Monday, he sent the band off-stage while he played the ballad "You and I", then called them back after its devastating crescendo, only to send them away again with the instruction to have a cup of tea while, alone, he showed us a song that didn't make it on to the recent Conversation Peace album. The song was called "Ms and Mr Little Ones", and it suggested that Wonder casually sidelines the kinds of melodies that other writers spend their whole careers attempting to uncover.
A degree of in-concert spontaneity must be difficult enough when you've got a nine-piece band to consider. Yet Wonder is prepared to risk chaos by playing fast and loose while 33 members of the Royal Philharmonic are ranked behind him. It's always hard to work out what kind of time session orchestra players are having at pop concerts, up there behind the perspex screens in their tails and with their headphones clamped on. Maybe they're right in the groove, happy as Larry. Or maybe they wish they were at home. Either way, backing Stevie Wonder must carry an additional nervous charge because the chances are at some point Wonder is going to shout: "Saxophone solo!" and you'd better be ready.
This happened on Monday during an astonishing performance of "Ribbon in the Sky". Wonder had begun it carefully at the piano, letting the words hang behind the beat slightly, so that they took on a gorgeous, melancholy weight. Then he clicked the song up a gear into swing and called for the saxophonist. The man did a nice job, though he looked a little astonished. Still, he was hardly alone in that.