You guys haven't heard him on a bad night.
That is a good night (with some studio doctoring). Sad, I know.
Coverdale, even in his younger days, was essentially a baritone singer. And what a rich baritone he had.
He could go high for short periods, but he didn't sing whole songs, much less albums or concerts and tours like that.
Purple knew this, they didn't want another Ian Gillan and there was always Glenn Hughes with his tenor/falsetto range who could do the high parts well (but to this day has no real authority in his voice in the low register). Ironically, when Coverdale left Deep Purple he said he "didn't want to scream my balls off anymore when singing". And inital Whitesnake stayed very much in his natiural range.
It all went awry when he split up the original Whitesnake and got into the fangs of John Kalodner. He implanted the idea in Coverdale's brain/vocal chords that singing high is singing well and Coverdale's gargantuan vanity went with it (Still that Glenn Hughes chip on his shoulder? Why I cry?). Following the Slide It In tours that for the first time cracked America a little (thanks to Keith Olsen's remix of Martin Birch's previous work), Coverdale's vocal chords were shot for the first time, too much singing outside of his natural range. He was close to losing it forever, but got specialist treatment (from the same guy who saved Klaus Meine's voice I believe) and an operation. Following that he was able to sing higher than ever (just listen to the 1987 album), but I already sensed back then that something was amiss, compared to his pot belly Whitesnake days, he strained hard. By Slip of the Tongue with its impossibly high-pitched vocals his voice was disintegrating, just listen closely to this here (from around the same time), in the studio, but still:
When he stays low it's all very well (the song was initially penned for Billy Idol to sing), but listen around 3.20. When I first heard that back then, I winced. Something like that would have never gone out in Purple days, it sounded like it hurt him singing it.
Things went from bad to worse from then on, Coverdale Page, for all its musical quality, was another vanity project as regards singing high. It was the time when Robert Plant would actually sing lower (which I like a lot better than his banshee stuff where you can never understand the lyrics), yet Coverdale went up another notch. Jon Lord, when hearing Coverdale Page for the first time, was baffled: "I cannot for the life of me understand why David with his wonderful register now sings like he is Robert Plant, he is not and he shouldn't. It hurts me listening to it." (Coverdale got the job with Purple on the basis of singing Nilsson's Everybody's Talking and The Beatles' Yesterday - both in a low register.)
Come the nineties, his vocals live were all strain, strain, strain, even frayed. There were a few exceptions.
(And didn't that mock Bon Jovi haircut and his natural color look so much better on him too? That album didn't sell at all, unfortunately.)
These days it physically hurts me to listen to him. I avoid Whitesnake concerts even as a DP diehard - and he used to be my favorite singer (I liked him better than even Gillan, never mind his less than skillful "Babe, I wanna ball you all night long" lyrics.)
I blame you Americans for ruining his voice. You and your silly Led Zep obsession. After all he is now one of yours, he adopted citizenship a few years ago. The pudgy boy from Redcar up England North.
I've said it again and again: Get a haircut, do old soul classics in the Michael Bolton, Rod Stewart, Joe Cocker mode, all with a little Tom Jones zest and innuendo, and you'd be able to sell ten times as much as with your Whitesnake nostalgia revue. And age gracefully. Like this guy does:
PS: Yup, that is Tommy Aldridge. He's been so often in and out of Whitesnake, I've lost count. Coverdale thinks he's a little too technical and cold and overplays, but when the last drummer left WS, he held a vote among the other musicians which drummer they would like to see play with them and Tommy won the vote hands down. I've never cared for his drumming much, be it with Black Oak, Travers, Ozzy or WS. Give me Ian Paice any day ... But Tommy is no doubt the right drummer for modern WS' "Larger than life and have every guitar chord sound like Godzilla is approaching"-modus operandi. Yawn.