I don't think that with Motörhead Lemmy's vocals have ever sounded better. I saw him with Motörhead in 1978 (Eddie Clarke line up) opening for a then still fledgling Whitesnake - Lemmy couldn't sing back then and sure enough he couldn't sing when I saw him again in 1983 (Brian Robertson line up) with Thin Lizzy (John Sykes line up) and Whitesnake (Mel Galley line up) also on the bill. He had his melodic peak with Hawkwind's Silver Machine - mind you, his voice was buried in echo on that track too.
Never mind, he's still an original. But even his bass playing was more melodic with Hawkwind too. If you listen to their early seventies live outing Space Ritual, Lemmy's tone is much less abrasive, his chording much more harmonic and daring and his (many) melodic lines very fluid - basically he solos throughout that live album in an almost Grateful Dead'ish, jammy way.
Uwe