Let's start this presentation with a short and funny video clip of my 1963 Favino, which then I just received the same day from a french collector.You will recognize Denis Chang, and what is hanging from the guitar tailpiece is one of my socks.
When you invite a demanding player like Denis Chang, you better make sure that your guitar does not rattle or generate parasite overtones from metallic parts.
I am presenting here tricks, some from Mario Maccaferri himself, to eliminate tailpiece rattling or tailpiece vibrations, which create unwanted overones and harmonics.Don't be afraid, I will not tell you to play your guitar with socks hanging below your tailpiece.
We all know Mario Maccaferri. He invented the Selmer petite bouche, the grande bouche with a resonator (not his best invention: I am talking about the resonator AND the grande bouche which present a lot of acoustic flaws whether the guitar is played accoustically or amplified). Mario had one trick he used on many Selmers and all most grande bouche. He was using a tailpiece fret. What's that? A fret is usually on the fretboard and that's not where the tailpiece is.
A tailpiece fret is made of ebony usually, and its purpose is to make sure that there is enough clearance from the tailpiece to the guitar top and, more importantly, to connect the tailpiece end to the very edge of the guitar top. I have been using this for years and it does eliminate tailpiece rattling and unwanted overtones, and does improve the sound of the guitar.
Obviously some of us will be reluctant to make this light modification. There are clean freaks among us who want to religiously keep the guitar in its original condition. Some other readers will not believe it's an efficient fix. Do your due dilligence and try a guitar before and after this modification. The proof is in the pudding...
The ebony tailpiece fret does not need to be longer than the tailpiece width and is often concealed below it so you do not see it unless you know there is one.
The piece of cloth below the tailpiece is also useful and covers the tailpiece fret top edge.
Also, on these pics below, you see that I am using the cable of my original ST 51 Stimer pickup to dampen the movements of the tailpiece. Free lunch, and very efficient also to fight the unwanted overtones, in addition to protecting the jack from snapping out of its socket while playing in a club.
Notice that the tailpiece fret does not rest on the binding (plastic) but on the guitar side (wood). The sound impedance using a plastic buffer is not good, but wood on wood is good.