First bass player that used foam under the bridge?

Carol Kaye says on her website and on interviews that she used a piece of felt, double folded and taped over her strings. I believe this would give a slightly different tone than a piece of foam most commonly stuffed under the strings.
You're right on with the p-bass and built-in foam. You can find pictures of this, they used the ashtray cover to hide it.

 

Tip 100 (from Carol Kayes website)

Hi Jeff! And thanks. About muting: The way I mute the strings is by folding over a piece of felt muting (buy at the sewing section at Target, Walmart etc.) so it's doubled to a width of about 1-1/2". Take it and tape it (I use masking tape) to on top of the bridge area, but laying slightly ahead of the bridges. It won't be too loose but you will have to re-tape it tighter from time to time. Thus, it lays on top of the strings and kills the over-and under-tones, making your bass sounds more defined. You use a doubled-up piece of felt *on top* of the strings when you play *only* with a pick. If you play with fingers (or even with fingers sometimes and then pick sometime), then get a piece of foam about the same width, but fit *underneath* the strings, barely touching the strings. This takes some doing.
You don't want the foam to mute the strings so much it gives off a "plunk" sound, yet you need it to touch all the strings relatively the same amount. The strings in all instances should ring almost as much as if there wasn't any muting at all. You'll notice an immediate difference in sound and your band will too as well as the audience noticing the bass sounding great and projecting very well too. In recording, it's a must. If you have a bridge cover and are using a doubled-up piece of felt, lay it between that rubber "mute" (that is practically useless) in the bridge cover and the strings, but....do raise the bridge-cover slightly so the strings ring....you will have to stick a couple of wedges underneath the bridge-cover so it stays up without rattling (I always used 2-3 picks).
This is the sound you want, a ringing sound but without all the extraneous noises of over-and under-tones, the strings get. This will work fine. You'll see my mute (with the "fancy" masking tape) in my pictures with the Aria Pro II (Steve Bailey bass), my bass w/Seymour Duncan Basslines PUs and Thomastik jazz flats.

 

A foam mute was standard equipment starting with the first Fender Precision basses. It was a strip stick-on foam insulation stuck to the underside of the bridge cover. The mute was included as standard by Fender for many years.

 

James Jamerson is also well known for the foam mute sound.

 

Cool Talkbass thread with pics.
History of dampers on Fender basses

 

I don't know about foam, but I'm pretty sure Tony Levin was the first to use a diaper mute.

 

You can get a professional mute for $20-$40, not sure if they come in custom colors, but these things weren't just thrown together in someone's cellar, they were developed using the latestet in computer technology and wind tunnel testing to outperform common handmade string mutes.

Or you can make me your own from felt and foam insulation for less than the price of a cup of coffee.

 

Many early basses had mutes. I think it was more as companies took them away, different players started gerry rigging them

 

Gibson '67 EB-3 had the mute built in that you could 'turn' on and off.

 

Weather stripping from a hardware store works really well. A roll of it is good to have for when it needs replacing.

 

I think the first person to use a mute was probably the first person to buy a 1951 Fender Precision. Rickenbackers still have built in mutes to this day, Gibsons came with them for years, many 50's and 60's basses came with them. I think Gibson stopped putting them on their basses when they switched to the three point bridge around 1973. Not sure about Fender. People stopped using mutes when the round wound string sound came into vogue, late 60's early 70's. They seem to have come back into fashion over the last 10 or so years, same with flatwounds, probably not a coincidence .

I bought a new 1970 P bass that came with the foam under the bridge cover. I use rolled up flannel now, you can control the amount of damping by how much you roll up obviously, most foam mutes damp too much for me, I like to just damp a little and to take the top off sometimes. Foam mutes are either on or off, no way to really control the amount of damping you get and they can buzz if the strings are not firmly against the foam, flannel doesn't do that. I have a bunch of them with varying thicknesses for varying amounts of muting and for different basses. Can't beat the price either. I've tried different things for mutes and like this the best, it's softer and more easily controllable, I will even use it on my Rics even though they have the built in foam mutes. The flannel takes about two seconds to put in and take back out.

 

I am not sure when they stopped doing this but I worked in a music store in the 1970's and the 78 p bass I bought had rubber foam on the Tailpiece cover. So this was done as late as 1978 and possibly later.

 

The first, at the time well-known, bassist was possibly Monk Montgomery. Simply because he was a very early adopter of the Fender P bass, and used it stock.

 

The original Jazz bass, until sometime in 1962, had adjustable individaul foam mutes UNDER the strings, so thats whoever got the fist Jazz Bass ca. 1959. The Precision had the foam mute on the underside the bridge cover from the start, so 1951 for OVER the strings.

Trying to determine the first person who did something like this is akin to asking who was the first person to fry chicken.

 

I have a Nordy mute, it's great, but it is also $50usd for just a piece of hard foam with appropriately spaced slices glued to a fancy popsicle stick . Mine is Wenge.

 

A related topic; given that Fender basses were supplied with foam under the bridge cover, who was the first known player to regularly play with the cover removed?

 

Exactly! Ahhh, like October 1951. Not exactly like a new idea.

 

I have this gruv gear "fump" mute or whatever they call it. I'm honestly not that into the way it sounds. It deadens too much on my basses (I suppose it depends on the bridge design, but my G&L bridge seems pretty standard/basic and it doesn't get far enough to the end of the string), and it just doesn't sound great. Very tick tack sound. Believe me, I WANT to like it, cuz I think it looks so poopie when you just cram foam under there, but I haven't found a "professional" option that works so great yet.

 

That first Bass-player, although I use the term loosely, who used foam under the strings would have been Leo Fender who wanted his bass to come closer to the sound of an upright bass. Over the years, he tried a number of different applications of mutes. My '65 Jazz came with an open cell foam strip glued to the Ashtray pickup guard. It hit the strings behind the bridge pickup and if I recall, it was pretty close to the bridge. Sorry I don't remember for sure. That bass was stolen from me in 1976.

I played it for a couple of years before I realized it was there. I removed the pickup cover/protectors to give my bass a good cleaning and saw that strip of foam. I ripped that sucker right out of there and suddenly I had some decent sustain for a change. I am NOT a fan of mutes on Fender basses although a lot of folks do like them.