Exactly how much should I know? Seems like a dumb question and 'as much as possible' is the obvious answer but how much musical theory would be necessary for a band?

I basically know major, minor, blues, all their pentatonics and chromatic scales...I've been playing for 3 years and I didn't start out by learning theory like I should, so I basically learned all that in one or two days...What are some other necessary things I should learn and what are they used for (What's their purpose in a song)?
learn musical keys. one you know what notes fall in a key, it makes it easy to move around the fretboard. also, know "relative major and minor keys." that is extremely important when writing melodies. there is a good website for music theory called "Theory on the Web" (don't remember the exact address, google it).

start learning all the notes on the fretboard too. boxes shouldn't be a substitute for knowing the notes. if you work at it, it's a about a two week process getting the entire thing down.

tonal music (the music we all play) centers on a tone: the first note of the major scale. All other tones (notes and chords) are judged by the human ear in relation to that tone. Ones that are more related to it (like the 5th note in the major scale) sound pleasing, ones less related sound sad (like the 6th) or just plain weird (like the tritone). also, never be afraid to venture out of a scale and add some notes whenever you feel like it. don't limit yourself.

get a handle on all that and off ya go. more than anything, it's about experience. and never get too analytical about music. it's all about the emotion, not about proving you know how to spell a Cadd9 chord.
Last edited by TarHeel90 at Aug 11, 2008,
It all depends on what style of music you play, generally (not so much what you need to know, but what is expected of you by people within that genre). For example, rock requires pretty much pentatonics only, blues (which sounds like what you do) requires mainly pentatonic and "blues" scales, and jazz requires as much theory as possible and then some.

Keep your genre in mind with theory, but pay more attention to the "theory people's" responses (e.g. tarheel90 up there).
Thanks guys. Some additional info:

I know all the notes on the E string pretty easily, I know the notes on the A string as well just not as...fluent as the E string. The D and G string, I basically just use the first 2 strings to figure out the notes (So say I'm on the 3rd fret of the E string...which is a G, I figure that the 5th fret of the D string is also a G).
I don't know how to read sheet music (I used to) but I don't figure that's too important. And I can play just about anything, except overly fast pieces like Donna Lee or some tapping tunes like Bloodmeat by Protest The Hero. I just need to work on knowing how to write. I can come up with pretty good sounding songs on my bass but I have no idea what I'm doing...I guess I know which frets go with eachother from experience, I just don't know what notes go with which and all that.

@ TarHeel: What do you mean by relative major/minor?

@Athetosis: I play pretty much everything from Jazz to Rock, to Metal to Hip Hop, and all that when I'm on my own, when I jam with a band or a guitarist, we mostly play rock...but it's weird, I know the most theory out of anyone I play with and I'm not exactly a genius when it comes to theory.
As far as intervals go, the whole "3rd fret E string = 5 fret A string" concept is a good place to start (that's what I did). The next step would be examining those scales further in context of the neck, starting with the major scales and moving to minor, then to others. I'd advise taking the scale positions (open, 2, 3, 5, 7, 8, 10, 12) and memorizing them in octaves; this cuts them into manageable chunks. As you grow familiar with these, you can extend those into two- and three-octave sections (horizontally, or same position). From there, you can take certain octave-length sections and merge them into others vertically (other fret positions).

As you do this, you'll remember certain notes/fret patterns, and those patterns will grow longer, helping you to feel more comfortable and natural when playing in a set key/chord structure. As long as you're sure to practice in different ascending/descending patterns with different intervals (whatever helps you enjoy it...that is, after you become proficient at the full scale ), your playing will become more fluid as you become more familiar with the neck theory-wise and it'll seem less like you're playing in a set pattern with which you're comfortable.

If you've got a good ear, then playing by it will often work, but if you get into certain genres, you'll need varying levels of theory knowledge and you'll need to know what notes you're playing instead of just the sound of them. For example, in genres like progressive metal, math metal, jazz, and classical, you'll need a decent amount of theory knowledge, though in jazz and classical you'll also be expected to be able to read sheet music.

Basically, what you need to learn is decided by what you want to play and how versatile you want your playing to be. Keep in mind that including techniques outside of the genre you're playing in will also help you to understand how the genres intertwine. This will allow you to include the "best" aspects of each genre in your playing style.

Hope I've helped some more, and sorry about the ridiculously long post. It's what I do.
Don't just know the shape of the scale. Know the intervals. Know that the major scale has all major intervals while the natural minor scale has a minor 3rd, 6th and 7th.

Know the chord progressions for the minor and major scales.

IV vii
iii - iv - ii - V - I

This helps you make chord progressions that always work.

Learn the cadences.

Learn how to construct chords and how to invert them.

That's just the tip of the iceberg.
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Learning scales helps. I never had any teachers so I just taught myself and the theory kinda camw with a load of practice. One day the penny just dropped and it all made sence.
Hard to say. Usually you need different amounts depending on what you play.

As a rule of thumb, you should know ALL the notes up and down the neck, and the formula for the major scale at the very least.
I suck at theory, but still, you should learn the "circle of fifths". That is what tells you what chords are in a key and such. Otherwise you have to memorize each one of them individually. The circle of fifths lets you figure out ANY key easily. I'm not even going to try to explain it, but this is what it looks like:

relative major and minor scales is easy. for example:

these notes are in the key of C (C major scale):


these notes are in the key of A minor (A minor scale):


because they contain the same notes, they are called relative keys. the sound of the scale depends on what note you start on. starting on C gives you the standard "do re mi" thing, and A is the sadder sound. play around and mix and match both to match the mood of the song.
try the book "bass for dummies". Serously, the way he explains the scales/modes/etc is great. Very digestible.

Just as an editorial side note, learn as much as you find interesting. When I discovered the differences between the scales, I could feel a series of epiphanies coming on, like peeling back the layers of an onion. Now, not everyone's palette can handle the inner part of an onion, but it might in the future.

What I am trying to say, is don't just set a goal of *learn the scales*. Make it a musical exploration. I compare it to how I (and a lot of people I know) learned electric guitar:

It's one thing to know how to play a particular song or riff; it's another thing to know *why* the artist chose to play a particular note/rhythm. Don't make the theory work, but work AT IT over time.
Quote by Milan999
Exactly how much should I know? Seems like a dumb question and 'as much as possible' is the obvious answer but how much musical theory would be necessary for a band?

There is no hard and fast rule; if you'd asked the mega stars from the sixties what theory and scales they knew 98% would probably have told you "nothing".

I played through the heady days of 'Beatlemania' where none of us knew any theory other than chords that we picked up from each other or a book, my basslines were built from chords, when I joined the British army in 1966 and became a full time army musician where I was taught theory etc things that I'd been doing became clear to me.

Theory is an international/universal language and if you do learn it stick to the correct terminology and you will be able to converse with anyone from anywhere don't corrupt it.
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