I'm only replying 'cos I hate to see a thread wither and die without anyone offering anything............
A small ask? yes you are joking. To sing like PR AND RP. Dream on!
In truth, there is probably someone out there that can do it just waiting for the chance. I didn't get back into it myself until later in life and regret that so much.
Your list is a who's who of what I do except for Percy and Joe who both sing (or in Planty's case) sang, pretty high. I don't think I would be arrogant enough to say I do the rest of them justice but I give it all I've got.
It is a hard task finding vocalists these days. They are there, but you have to look real hard and if you find someone with potential give them all the support and help you can.
What I have noticed over the years is band members are quick to tell you when you are crap but rarely give creative feedback on what you are trying to do.
Even though this stuff can be regarded as 'old man's music' it is classic and a younger singer will catch on fast because there is sooo much scope in the songs to stretch out.
My suggestion would be to find someone younger who is just up for it. The first time I heard Davy Knowles I thought he must be 40+! or smoking 40+ a day!
I'm currently looking for someone to replace myself so I understand the problem. I scan the faces and if I see somebody singing out with me I try to nab them to ask and see if they want to really do it. Like with anything, you do need to have some ability or at least a 'feel' for the music, but a lot of it in fronting bands is also about having the bottle and being prepared to work at it to find the best in you.
I've just been listening to Slash's album and whilst it is a guitarist's solo effort the songs have been written and co-written to showcase performances and their are some superb vocal contributions on this album. The great thing about Slash is that he is a contemporary artist of today but he digs all the people and bands on your list.
Get somebody young who identifies with him and give him a hard rocking band to front and watch it happen.
Wish you luck in your search
No Hits, No Hype.......................Classic Rock Jan 2012
