It's exactly what Phil and Felipe are saying. You basically learn to use your full voice and then learn how to color the voice differently from THAT position. When you color the voice from a full voice set up, you will still keep your support in place instead of singing for 2 or more different places. Think of M2 as being more of a vocal effect that you just use occasionally from time to time, not something you base your entire technique off of (unless you're only ever looking to sing Bee Gee's material).

Actually the whole problem is that we should not be so worried about the mechanical register, but instead resonance and intensity and just keep using your voice normally. But headvoice=flip/falsetto is the first idea that will come to the student because, on the begining, that's pretty much all that we can do (if you can, I couldn't even do that lol).

As for versatility Owen. You cannot get more versatility than a properly developed full voice. Because then all the comments from people saying "one voice, no bridges" finally starts to click. Rather than switching "modes" you just change intensity/weight. If I want to be in pure headvoice by G4 I will just pull off heaps of weight and intensity to the sound.

And just to clarify, when Dante says staying in chest he means that the resonances are still mixing (mixed voice).

As Felipe and Phil have mentioned, the way you want to THINK about approaching this is treating it as though you're going to stay in M1 the whole time, and just learning to control that. Trying to think M1 for one song (or even part of a song), then M2 for the next, then back to M1 for the next one after that, etc. is a fast way to make you very inconsistent when singing live. The voice likes for you to choose more or less one way to sing in a live scenario and stick with that. When you start going back and forth between approaches, you will begin to have one approach bleed into the other when you don't want it to! You will also find it hard to get out of a particular "mode". Just learn to do it all with your full chest connection.

you simply cannot get away with this with anything other than fullvoice if you want the sound he has on the album like I posted here. You don't go to falsetto if you want a full, chesty sound.
Straight up belting/mixed voice whatever you want to call it.
it is a connected sound. as you go higher the voice thins out and you can control how heavy or thin you want to keep it up top whilst still being connected to your full voice.

I used to sing Stairway to heaven too and the way i did it was very similar : full head on high parts. While the C and E 5 would sound ok, my voice would lose its qualities on A4s. As your voice is lower than mine, your head voice might be strong enough not to sound too whimpy, but you could just go for a light mix instead, with weigth shedding on the high Cs, or full head on the high Cs and high Es.

My advice is still not to go full head until at least B4 for this kind of singing.

I also used to sing Rock and Roll and what Felipe says is true. This light approach doesn't work well. I have lately sung this song in a light mix but if i had to do it now, i would opt out for something chestier.

This thread reflects well the skills and versatility of Robert Plant who could blend very different singing styles depending on the songs or even throughout his career on the same songs.

While he did use a lot of things in falsetto that are a kind of a hallmark of his style, if you try doing the same on a song like Rock n Roll, it will just not work.

Anyways if the idea is training to achieve a similar result, the route would be the same, just directing more efforts towards that kind of quality. You can not skip the "M1 head voice" part because in fact most of the work you do there is improving your coordination and eliminating tensions that are unnecessary.

http://www.youtube.com/watch?v.....kNeD4Sv798

This was live June 1972 in LA I believe, awesome live version but you can hear the difference between the approach here and then listen to the studio version. Way brighter and slightly more nasally and clean than the studio takes.
http://www.youtube.com/watch?v.....QTaHw941iY

This is probably my favorite live version of this song. Same scenario here.

Anyways, to me its sounded like in the early days, he used more of a chest heavy belting sound. Even on the highest notes like the countless G5s he still knew how to "pull chest resonance" up into his head voice and end up with a really consistant sound all the way to an A5-Bb5

http://www.youtube.com/watch?v.....hwSEVbBZl4

http://www.youtube.com/watch?v.....YAtbROFfqU

The G5s/G#5 glissandos are out of this world! Almost like a power drill. It came so easily for him back then. Ken Tamplin said that he used a lot of mask back then to help shed the weight as he went further up his range. If you look at his live clips, you can see he's smiling into the sound, letting it resonate in his nasal cavity as hes doing his big belting sounds. The formative years of live Led Zeppelin 1968-1970 Robert Plant sang his ass off at every show, hitting most of the notes in songs heard in the studio versions and oftentimes more. However, around late 1970, Robert got a bit fatigued in the voice for the last half of the North American tour, which is to be expected. He came back stronger than ever and did some stellar 1971 shows plus the second half of the amazing 1971 BBC sessions which anyone should pick up if they want to hear early live (Zeppelin/Plant at his peak) at their best. Unfortunately due to his lifestyle of many rockstars from the era, he blew out much of his voice around late 1972-73 from a combination of lack of rest, drugs, sickness, and lack of sustainable technique. He does have some of his range recovered nowadays, but hes just not quite as powerful as he was when he was younger.