I have great appreciation and admiration for your post regarding HP. I always want to post 'Thirty Days' to represent their work, just a masterpiece of a tune but I think someone else did that quite a while back. If I could roll back time, one of the things I would try to make up for are concerts I wish I had taken in, and they are at the top of the list. I loved Steve Marriot and he would also be in my top five of vocals.The Talk Box is an amplifier and the speaker is "covered" and comes out through a tube that you put in your mouth and then the microphone picks up the sound that comes out of your mouth. They work, in a way, like the people who lose their voice box due to smoking.
And, Humble Pie is one of THE BEST rock bands ever. Steve Marriott is in the Top 5 list of all-time vocalists. I kinda prefer Humble Pie with Clem Clempson than Frampton, but it's close. Rockin' The Fillmore is an iconic rock album.
Curious if Paul Rogers is in your top five as well.