Electric Chili

I was searching around the net this morning searching for some popular chord progressions.  Below are the ones I found.  Let me know if you have any more to add to the list.

I-II-iii-iv “Longer” Dan Fogelberg
I-vi-ii-V “Please Mr. Postman”
I-ii-V-I
I-ii7-V-I
I-IVmaj7-V7-I
I-vi-ii-V-i
I-iii-vi-ii-V7-I
I-iii-vi-ii-V-I “Alices Restaurant” Arlo Guthrie

Minor Progressions
i–V–i–iv–i  “Black Magic Woman” Santana
i–bVI–iv–bVII–i  “Mr. Jones” Counting Crows
i-IV “Oye Como VA” Tito Puente
ii-V-I “Autumn Leaves” standard

DECEPTIVE CADENCE PROGRESSIONS:
I-iv-vi-V-iv
I-ii-V-vi
I-vi-iii-V-vib

DIMINISHED CHORD PROGRESSIONS:
I-IV-IVdim7-I
I-ii-viidim-I
I-I#dim-ii-V-I

INVERTED CHORD PROGRESSIONS:
1.C C/E F G C
2.C G/B F/A G C
3.C G/B Am F G G/B C
4.C G E/G# Am G/B C

SECONDARY DOMINANT CHORD PROGRESSIONS:
I-VI-ii-V-I
I-III-VI-ii-V-I
I-IV-II-V-I
I-II-V-I

MODAL MIXTURES PROGRESSIONS:
1.I-IV-iv-I
2.C C/E Fm G C
3.I-IIIb-IV-V-I
4.I-IV-iiidim-V-I

I was surfing along this afternoon and came upon this article over at The Boston Globe.  He describes the vi-IV-I-V as the Sensative Female Chord progression…lol.  He’s absolutely on the money!  I won’t rewrite his article here so head on over there and check it out.  I like it in Am where it goes like Am F C G.  That’s the progression in Joan Osborne’s “One of Us”.  You know…”What if God was one of us…”

I was surfing around looking for common chord progressions that I can solo over using my RC-20 looper pedal.  I found a site that had an interesting chart that I’ll be “playing” with for a while.  The first picture below is the Major chord pattern flow.  You can start from anywhere on the chart, just pick a chord within the key your playing and then follow it from left to right.  When you get to a bracket, you need to choos whether you’re going to go with the upper chord or the lower.   Now when you’re done with the I chord and you get the the *.  The astericks means you can then go to any chord.  If you’re doing a repeating pattern you may likely go to where you started. 

Below is the Minor version of the above chart.  Note that it adds the VII chord and shows that the best way to get there is from the iv which means the minor iv chord (lower case is minor)

Let’s play with these for a minute and see what sort of progressions we can come up with.  Let’s start with the easiest which I think is the key of C Major which means we’ll be using the upper chart.  Lets pick E to start and see where this takes us…

Em (which is the iii) which means it really needs to be Em
Am (vi)
F (IV)  I chose the lower path in the brackets
G (V) (I chose this route rather than the diminished becuase I’m not so good at grabbing a diminshed chords…need to work on that)
C

You’ll have to grab your guitar and give this a quick play to see how it sounds.  I’ll grab my ukulele since it’s sitting here next me.

But that’s how it works folks.   Hmmm…before I go…what sort of scales can we play on this progression?  Sounds like a topic for another post in the near future!

Later!

I was playing around in LT Spice Model of the famous Fuzz Face pedal circuit.

The circuit is brilliant in its simplicity. The first transistor in the signal path is biased as a high gain amplifier that feeds the base of a second transitor which provides a voltage feedback to the base of the first transistor.   Note that the transistor model I used is suppose to be similar to those old germanium ones used back in the day.  I can’t really vouch for these models though.  I found them somewhere on a forum so the origin of the models are somewhat nebulous.

This is a pretty easy circuit to start with if you interested in putting together your own pedals.  You can built this circuit youself in a few minutes with some old parts you may have laying around.  If you don’t have these sort of parts laying around you will soon be able to buy them in the Electric Chili store.

Take a look at the output waveformbelow.  It almost looks like I just generated a square wave.  It has a solid pattern which is good musically.  We don’t want anything that’s a hot mess because it’ll sound like crap.

Check out the FFT below. The blue sinewave is the simulated input. You can see that the input isn’t modeled as a perfect sinewave but that’s OK. We’re unlikely to get a perfect sinewave out of guitar. In face, if we did, we would hate the sound. It would be pretty darn annoying.  The Blue wave is the output of the circuit.  You can see that it sustains many of the high frequency signals.  This makes sense because of the hard edges on the waveform.

The model is set up so we can see different pot settings can be evaluated at the same time.  Pretty slick eh?  Here’s a copy of the model itself so you can play around with it yourself.  Change the resistor and cap values and take a look at how it affects the output.  Throw a diode in a strange place to see how if affects the signal.   A tool like this is a great way to learn about how analog circuits work so if you haven’t downloaded LT SPice, you should Google and get it!

I’ve decided to take Electric Chili in a little different direction or maybe I should say little different focus. My intent at first was to provide information about guitars, gear, and learning how to play. I think I might have bit off a little more than I was willing to chew. The world of guitars is huge and who could possibly handle it all without a full time staff of writers. There’s just no way one guy can really pull off what I had in mind. Well, how do you really know unless you try right?

So here’s the background…after a little work on putting guitar effects pedals up in the store (and ebay), I starting doing a little research about what I was selling as well as doing some reviews. In my research I found several communities of guitar players that enjoy creating their own effects pedals. I never knew this interest even existed. As an working electrical engineer I find this to be absolutely fascinating and want to jump in with both feet! So that’s where I’m going! I want to develop some of my own pedals as well as offer platforms and parts for developing guitar pedals. That’s my new focus. I admit that I’m somewhat ADD in my interests and move around quite a bit so we’ll have to see what happens.

My first project is to develop an effects development box that incorporates a breadboard inside so that tinkering with different circuits is extremely simple. From there I would like to see what can be done with PICs in the way of modifying guitar audio signals. I’m having a good time just thinking about the possibilities!

Eric gives us a fine version of this Otis Rush classic from an abandoned documentary ‘Nothin’ But The Blues‘ by Martin Scorsese.

Being an engineer, I can’t help but enjoy digging into the origins of things we take for granted today.  I like to pay a little homage to the inventors who came before us.  With that being said, let’s take a look at magnetic pickups.  It seems that magnetic pickups were first invented for the purpose of improving record players.  The pickups would “pick up” the variations of the needle as it tracked the record.  This needle would move within a magnet field and generate a current.   It wasn’t until 1932 that a patent for a magnetic pickup appears in the patent record for an “Electrical Device Musical Instruments”.  The inventors name was Armond F. Knoblaugh.  It appears that although he is credited with the patent, he was working for Baldwin.  This is pretty typical in the engineering world.  The inventor is credited but the patent actually belongs to the company they work for.

He kept it general enough so that it applies to all musical instruments but the illustrations in his patent primarily show the the strings of a piano plate which makes sense for a Baldwin engineer.

Let’s hear a little from Armond about his invention…

My invention relates to the class of instruments in which the mechanical vibrations of strings or like members are transformed into electrical vibrations, which are amplified and 5 converted into sound by a loud speaker or the like. In a co-pending application, Serial No. 581,416, filed December 16, 1931, I have described a series of individual magnets which give excellent results. In the present 10 invention, I have made magnets, each in connection with a plurality of strings, that taper in substantially the same ratio as the lengths of the strings.

The first reference that I could find where the pickup was used for something that resembled a guitar was in 1934.  Check out that photo to the left.  Not a real “looker” but you get the idea.  It has the basic shape of a guitar that we’re familiar with and even has six strings.  This was patented by G. D. Beauchamp who was the cofounder of Electro Stinged Instrument Corporation. 

G. D. Beauchamp was also one of the founders of Rickenbacker Guitars.  He later went on to develop a patent for electric guitars in 1937.  If you do a little patent searching you’ll see that that is the time when patents for different types of electric guitars began.  That’s how it works in the patent world.  If someone can find a little different way of doing something they can get a patent of the own.  For example, if I think the pickup works better at the neck than at the bridge, I can apply for a new patent.  If I come up with a design that offers flexibility on what pickup I use, a new patent is born.

So now that the whole Magnetic Pickup is out of the bag, so to speak, patents start to come hot and heavy.  Gibson joins the party in 1939, Radio Corp  and Gibson again in 1941, and Radio Corp again in 1944.  If you wondering who the heck is Radio Corp, just think radio and Marconi.  They designed and manufactured radio equipment and ultimately were bought out by GE.

In the 1944 Radio Corp patent you can see that even improving something is enough to get you a new patent. 

In this application I disclose an improved method and means for obtaining a greater range of timbre in an electronic musical instrument, using mechanical vibrators such as strings, reeds, rods, plates, bars, membranes, etc.

This patent shows how the inclusion of capacitors and inductors can affect the response of the pickups.  The artwork shows the locations of these passive elements but in typical Patent form, doesn’t show you the values or the frequency plots that show you exactly how it improves it.  But anyway, I digress. 

So, there you go.  Magnetic Pickups go back quite a ways in our history.  We haven’t talked about the difference between the single coil and the humbucker but will certainly get to that in another post.

I found this video which has some pretty good information about how to adjust you truss rod.  Be careful!  Broken truss rods are a very common occurance.  I’ve never broken one myself but seem to run into them all the time when friends ask me to take a look at their setups.  A misconception is that ratcheting on you truss rod can improve you action.  The truth is that you need to make minor adjustments and then check in an iterative manner.  If you crank too hard, it WILL break!

Tune the guitar up normally. Play the 12th fret harmonic, and compare it to the 12th fret note. If the Fretted note is Flat, move the saddle Forwards(towards the neck), and vice versa.
If you have a 6 saddle bridge like the one shown to the left, you’ll be able to adjust each saddle position independantly. If you have a single saddle, like most acoustic guitars, adjusting the saddle will affect more than one string so small adjustments need to be made and then rechecked after you work on the next string. Note that it’s probably a good idea to loosen you strings a bit before you attemp to move the saddle. This will help to prevent messing up the screw heads. 

You should consider setting the intonation when you change the gauge of strings you use.  The thickness difference can play a role in changing the intonation. 

You really should check your guitar manufactures web site for any information they have about setting the intonation.  Fender has pretty detailed instructions but is a little overwhelming.  Others are the same way, but you should check them out anyway just to make sure you’re not missing anything.  My experience, however, is that if you follow the steps aboove, you’ll be happy with the results.

Robert Leroy Johnson (May 8, 1911 – August 16, 1938) was an American blues musician, among the most famous of Delta blues musicians. His landmark recordings from 1936–1937 display a remarkable combination of singing, guitar skills, and songwriting talent that have influenced generations of musicians. Johnson’s shadowy, poorly documented life and death at age 27 have given rise to much legend, including a Faust myth.

Johnson’s songs, vocal phrasing and guitar style have influenced a broad range of musicians; Eric Clapton has called Johnson “the most important blues singer that ever lived”. Johnson was inducted into the Rock and Roll Hall of Fame as an “Early Influence” in their first induction ceremony in 1986. He was ranked fifth in Rolling Stone’s list of 100 Greatest Guitarists of All Time.

Article Source: http://en.wikipedia.org/wiki/Robert_Johnson_(musician)