It begins inauspiciously, if hilariously. A tide of thick white smoke floods out from beneath the drum riser, spilling over the lip of the stage and engulfing the first five rows.
The attempt to swathe Angie Stone's beguiling, ethereal soul music with mystery and intrigue has turned into some sort of comedy version of Quatermass And The Pit.
But in a way it's entirely appropriate. Stone's brilliant 'Black Diamond' album can intimidate listeners, its pristine sheen at first masking the depth of feeling and meticulously understated musicianship within.
But there's nothing like a bit of unintentional slapstick to break the (dry) ice - and, while Stone has plenty serious to say, she also came to have a good time.
This much is clear within minutes, as a spine-chilling introduction - Stone and her three dazzling, interweaving backing vocalists harmonising on 'Amazing Grace' from off stage - gives way to a few bars of James Brown's 'The Payback'.
What follows is an hour and a half of peerless down-home funky soul music, Stone very much the focus but her beautifully relaxed band managing to turn the Apollo's recalcitrant spaces into somewhere almost as intimate as a Pentecostal meeting hall.
But it's Stone herself, her evident warmth and humanity allied to a resolve that's kept her involved in making music since the late '70s, that captivate. Every syllable is made to count, and not one ounce of anything superfluous is tolerated from her band.
Towards the end she brings on her three-year-old son, Michael, who seizes a microphone bigger than his forearm and begins to rap. He steals the show, somewhat inevitably, and takes some persuading to leave the stage: a career in the financial services industry is not, one suspects, in his stars.
But amazingly Stone ratchets the show up another final notch, a blistering reading of 'No More Rain (In This Cloud)', dedicated to the toddler she says has brought sunshine back into her life, becoming an explosive hymn of heartfelt joy and release.
The band line up across the stage, hand in hand, and Angie and her backing singers deliver a final prayerful a cappella finale. There are calls for more - how could there not be? - but there's no need. This is pretty much perfect.
