Why is this style of old microphone shaped this way?

I had several rock and roll bands back in the 60s. we used this identical microphone and it was a great microphone. it was a unidirectional mic. meaning, it picked up surrounding sounds, as well as the vocal, and amplified them as well. the only problem with this microphone was feedback. we were limited on our volume control because of this. the shape of the mic was just a sign of the times. the really odd-looking directional microphones were about one and a half feet long. most were used for television applications. to see this, visit Youtube and the rock and roll show Night Train.

Yes it’s a feedback issue as @john65pennington says. When rock invented the non instrumental frontman, he wanted to prance and dance all over the stage with microphone in hand. That would only add to the feedback with a mic like this.

A singer’s biggest problem is hearing themselves over the instruments. Not doing so increases the yelling, but decreases the singing. That’s why many wear earplug monitors now even on stage.

I also think rock took well to the phallus symbol of the cylindrical mics, regardless of their directional capabilities.

It’s also just beautiful.

so this shape is strictly utility based around omni directional functionality?

Yes. It hails from big band days where they wouldn’t bother to mic every instrument, but rather mic for balance of entire room.

Modern music mics everything and wants to channel every sound as unique. This makes for separate channels that can be mixed easier later on.

It also makes a difference for live shows. In the old days, concert halls and music venues were specifically designed with acoustic favor. The rooms were meant for sound. The old mics simply accentuated.

But not only does modern music have special effects needing separate sound channels, but many times a venue is in the seedy part of town in the basement of an old bar. The room is not designed for live music. A talented and high quality sound man will take separate channels of music and mix out impurities of the room resonance, thereby overcoming the challenges of pillars being in the middle of a room, or exposed brick causing reverb where it’s not wanted.

@RealEyesRealizeRealLies thanks!

This page has photos of dismantled Shure Unidyne mics
http://scottymoore.net/shure55s.html

Here’s a 12-page booklet, The Unidyne Story (PDF, 450K)
http://www.coutant.org/shure55/unidyne.pdf

@Ltryptophan I just realized the 12-page booklet talks about the creation of the mike, and why it is shaped that way and how the openings affect the sound. I did not read the whole thing before posting it.

I assume modern copies of the mike are different, and the housing is just cosmetic, but the original 1939 model depended very much on the shape.

It’s technical beyond my understanding, but here’s a taste:

Bauer’s Unidyne design was configured so that the microphone had a series of front and rear openings which allow sound waves to reach both sides of the element’s diaphragm. The sound waves reaching the diaphragm from the rear had a longer path and passed through openings which produced a time delay between the sound entering from the rear and sound waves striking the front of the diaphragm. By varying the amounts of acoustical resistance encountered at the rear openings, Bauer was able to achieve cardioid, supercardioid, or hypercardioid patterns using a single element, and the first true unidirectional dynamic microphone became reality.