Prepared bass - - what the hell is that? Well one could also use the term "extended technique" bass for this is about.
What it means is putting stuff in or on the strings to create different colors, sounds and textures with the instrument (by the way, i am by no means the first to do this, this sort fo thing has been around for a while). It can also mean use different things to activate the strings.
One thing to keep in mind is that this is NOT gonna work for your run-of-the-mill pop or jazz music - - no disrespect meant here, just an acknowledgement that these sounds are fairly esoteric . . .
All of these techniques can also be used with effects - - found on the gear page.
There are a few ways to break this down. I'm gonna start with these and see what else comes to mind.
It's helpful to remember that, since I use piezo pickups under the bridges of my basses (see the gear page), I get a lot of body resonance and other nuances of sound that magnetic pickups will not get on their own. In other words, you may not get the same results from these techniques that I do. That being said, I've been using some of these techniques for almost 20 years - - way before I had the piezos in my basses.
The key to all of these techniques (or, really, the concept behind the techniques) is to experiment with different things, find out what you like and then use them to make music/sound/noise. They do take time to really come up with musical uses - - they are NOT a gimmick in my mind.
This would be things that you put into or on the strings.
Alligator Clips: These can get a nice gamelan or kalimba, tabla, or other tuned percussion sound. The heavier the clip (see test clips), the more it deadens the string - - but it can also make the note of the open string more pronounced. They sound really different at different places on the string - - closer to the bridge or neck will get really different sounds. You can also tune the open strings as chords with these. They come in slightly different weights or types of metal and I've converted some by putting gaffer's tape on them to further deaden the string (gets a much "woodier" sound). I've gotten really nice sounds from these by striking the strings with spoons or small pieces of wood like chopsticks. - - depending on the type of metal or whether they have tape on the clips, you can some really nice bell sounds or marimba-like sounds. I've also tapped on the fingerboard while these were on the strings and it sounds pretty amazing; when tapping, using fretless or fretted basses can really make a huge difference (and you can, of course, bend your percussion parts using fretless). I've also used these when deadening the strings with my left hand while doing slap technique with my right hand.
Test Clips: These are like alligator clips, but are smaller, meaning that you get a little more tone or note out of the string. The test clips can also yield more interesting differences between the string sound and the sound of the node where the clip meets the string - - they kind of fight each other and can get some really interesting harmonic sounds.
Binder Clips: The mini size are what really work here. They get a similar sound to the alligator and test clips, but (especially when placed very near the bridge) they get a sound with more buzz to it.
- - I've used all three types of clips on the Minim and Stigtette discs, as well as the Homler/Liebig Duo disc.
Upper Left: Binder Clips (mini)
Bottom Left: Test Clips
Upper Right: Alligator Clips (note gaff tape on teeth)
Bottom Right: Alligator Clips
Tambourine Jingles/Zils: (I used to call these tambourine tangs, but have learned that is incorrect.) Putting these in the strings and striking them with a mallet or stick (and different sticks get different sounds), or even your fingers, can yield gong-like sounds. There's a lot of low end and sustain in there, so you have to be careful. Also, the thickness of these is extremely important - - the best that I've used I got from a percussionist who said they came from a pretty cheap African instrument. I have some heavy brass ones and they just kill the string resonance - - so for me they are currently unusable.
- - I've used this technique the Minim and Stigtette discs, as well as the Homler/Liebig Duo disc.
Different Tambourine Zils.
You can't really tell from the picture, but some of these are concave and some are flat. Flat ones DO have a different sound. I have different metal ones (shown here) and even some wooden ones.
Chopsticks: Weaving these through the strings can get some really interesting sounds. They can sound somewhat similar to the clip, but have a woodier sound and seem to have less pitch component to them. This sound is better with fingerpicking with the right hand than it is with tapping on the fingerboard as the string height and resistance is changed considerably.
Popsicle Sticks: You can weave these through the strings as well. I like to do one stick going under-over and another going under-over to get maximum string modification. This sounds pretty good with muting with the left hand while doing slap technique with the right hand.
Kabob Skewers: Very similar to the chopsticks and popsicle sticks, but have a slightly different sound due to different shape and weight/mass.
Besides the usual, fingers, thumb and pick ways of getting the string to move.
Slides: I have metal (brass and steel) and ceramic slides, and they each get some different sounds. Besides the usual sort of bluesy thing you can get, you can also get some nice high arching melodies with them. They are also really cool if you use the butt end of them (where your finger normally goes) and use that on the string - - I like to do this really high up above the fingerboard and play really high squeaky melodies. You can also use this technique with fuzz for shard of noise.
Chopsticks: On fretless bass, striking the strings with a chopstick and doing glisses can get an interesting koto-like sound. It can also be used with fretted bass, but the koto sounds is a sounds I really love.
- - I've used this technique on the Minim disc, as well as the Homler/Liebig Duo disc.
Hard Plastic Tube (like a straw)
Top Right: Ceramic Slides
Middle Right: Brass Slides
Bottom Right: Metal Slide
Spoons: You can use these on the strings or to play things on the strings - - like the alligator clips, etc.
Meat Tenderizer: I have mini tenderizer tat was given to me (I think it was part of a toy set) and rubbing it across the strings can get some really heinous sounds - - really excellent with fuzz!
- - I've used this technique on the Homler/Liebig Duo disc.
Different Metal Spoon (note gaff tape on back of the left-most spoon, does give it a different sound)
Meat Tenderizer (from a set of toy kitchen utensils)
Rolling Pin (from the same set)
Not shown are plastic spoons - - which do have a different sound, especially with tape on them
Mallets/Drumsticks/Etc.: You can beat the living heck out of your strings with these - - both with stuff in the strings and just fingering notes. It can be a very powerful sound.
- - I've used this technique on the Minim disc, as well as the Homler/Liebig Duo disc.
Rhythm Stick: It's basically a drum stick with grooves cut in its sides - - rubbing it across the strings gets some really cool textures.
Super Ball on a Skewer: This is an old percussionist trick. The closest thing that it can be compared to is wetting a finger and drawing it across a conga. Can use be used on just the strings or on strings with stuff in 'em.
Stick Bundle: It's what I call those little stick thingies that drummers use. It can sound really good on things like the tambourine zils - - sometimes it sounds good on other stuff as well.
Japanese Dish Brush
Super Ball on Kabob Skewer
Ridged Stick (picked up in L. A. Chinatown, don't know what it is)
Tambourine Jingles/Zils: Aside from the "gong" use mentioned above, you can also get really nice scraping sounds on the string from them. Use properly, it could sound like the door being ripped off of hell.
Playing the Body of the Bass
Some of these absolutely need the piezos.
Super Ball on a Skewer: It sounds pretty darned cool being dragged across the top of the bass body.
the Homler/Liebig Duo disc.
Mallet/Stick/Etc.: Hitting the bass body with these is a cool sound, but not for the faint of heart.
Hands: With the right finish on the bass, one can rub one's hand across the top or the horns of the bass and get some really nice sounds. Also, I've gotten some really nice bass drum sounds by hitting the back of the bass with it on my lap.
Playing Behind the Nut/Bridge Pieces: This technique can get some really nice chime-like sounds. You need a fair amount of high end boost or overdrive to really make it come alive.
- - I've used this technique many, many discs