Out of the blue today I began describing the bridges to a student using new terms. There is so much conflicting terminology around the bridges that it is difficult to have a discussion about them without first defining terms.
Bridges of course are the 'zones of change' where the voice feels unstable, and the feeling of the resonance changes rapidly.
What often concerns me is the numbering of the bridges. Eb3 is of course primary in feeling, but counting from the bottom, where does the first major shift occur in the voice?
Now I am a great believer in the unity of the voice, and that by by singing right we can use a blended resonance throughout the range, and so minimise the effect of the bridges. Nevertheless the resonance shifts can still be felt and heard in the voice.
Some teachers may say that lower male voices experience the 'first bridge' around Ab2, while the higher males experience first bridge at Eb3. The occurrance of an Ab2 bridge is regarded as rare. Other teachers routinely call Ab2 'First Bridge'.
Most teachers would agree that carrying too much weight or muscle into the upper part of first (lowest) register will cause a problem at the Eb3 bridge. So a shift in resonance, or a lightening of tone, or a 'shedding of weight' is advocated as the Ab2-Eb3 zone is traversed.
The problem here is that a big majority of male voices need to do more than shed weight. They need to sit firmly into a strongly blended resonance. It is one thing to pare away some 'weight', and another to fully enter the middle voice at A2 or so. The mental attitude is quite different, and as we know, mental attitude is what controls the voice. Full acceptance of the increased head-resonance proportion transforms this zone from 'top of chest' to 'bottom of middle', leading to an easier more relaxed and very stable sound that the singer can dig into for rich tone or belting.
Once this 'Ab2 release' is established, release over the Eb bridge becomes much easier. In effect, we pair up the Ab2-Eb3 zone with the Eb3-Ab3 zone, and get a sort of 'power octave' where the voice is consistent and flexible, minimising the effect of the Eb bridge. If we just 'shed some weight' off of 'chest voice' we are still trapped in the unhelpful 'up/down' thinking which divides the voice at the great Eb3 tipping point. In nearly all male voices, excepting a few exceptionally high voices, head resonance increases from Eb2, and leading to a 'bridge-like' note at Ab2 and a firm second register feeling by A2.
Well... this post began with the terminology. I don't really like calling Ab2 the First Bridge, as this is against the current of common usage. John Henney once referred to this as a 'sort of half bridge'. Well the Eb3 bridge seems more disruptive, but there are other acoustic factors in the vocal tract that cause much of this difficulty, and when we sing correctly these issues (acoustic resistance in the trachea... a kind of cancellation of the sound... I'll happily explain this to anyone who wants to know...) are easily overcome. This leaves us with an Eb3 bridge which feels very similar to the other bridges. So to my mind they are all bridges, starting at Ab2.
Nevertheless today I was describing the low Eb2-Ab2 shift as 'Transition', and numbering the other bridges as usual, I=Eb3, II=Ab3, III=approx D4 and so on. I think this will be less confusing for my students if they work with SLS teachers as well. But I will still refer to the register starting on A2 as 'middle voice.'