12-Bar Blues Progression

[Angus]

I
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IV
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V7 --IV --I
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This is the formula (or whatever it's called) for the 12-Bar Blues Progression scale. Each line represents a beat, and each set of 4 lines represents a bar (hence 12-Bar Blues). Now the thing I'm having troubles with, is do I play EACH beat (which would be striking the strings 48 times)? Or, is there something I'm missing? Please help me, any help is greatly appreciated.

P.S. - The hyphons ( - ) before IV and I are there only for spacing, so Ignore them.

[WayOutThere]

The way I figure it, each "bar" is the pattern you want to strum, roughly. If you strum it just straight, four beats, you get a basic sound, but it might not be much. For example, when I practice along to, say, "You Shook Me" by Led Zeppelin--(I just work along on the rhythm. I'm a long way from Jimmy Page and the screaming leads and solos he does, trust me)--I do (given that I'm right in assuming E is the I, A is the IV, and B7 the V7):
E, E, E, E-A-G for each bar...then A, A, A, A-G, then switch back to E. I began practicing to it with just doing E, E, E, E--in rhythm with the song. It's a decent song to practice to, if you have it or want to download it.

I know I got off track. I think that it's just, anything. At the most basic, it would be strumming four times. You could, however, quickly strum eight times for each four beats (like eighth-notes), or strum a different pattern to your liking. (Personally, I like the typical style--as characterised by, i.e, "You Shook Me.") But it's hard to say without being able to play the record to you and mention it. (And, there's always the chance I'm wrong.)

Also: Maybe we learned two different things, but I thought the progression was:

|I |I |I |I |
|VI |VI|I |I |
|V7|VI|I |V7(if repeating)/I(if ending)|

Either way, hope I helped a bit.

[drwscefn]

an example that everyone knows is the Batman theme tune (old 60's camp series version)

In G,

Riff 1
E-----------------------------------------------------
B-----------------------------------------------------
G-----------------------------------------------------
D-----------------------------------------------------
A-----5-5-4-4-3-3-4-4(four times)-----------------
E-----3-3-3-3-3-3-3-3------------------------------- Thats your 'I'

Riff 2
E-----------------------------------------------------
B-----------------------------------------------------
G-----------------------------------------------------
D-----5-5-4-4-3-3-4-4-(Twice)------------------
A-----3-3-3-3-3-3-3-3---------------------------- Thats your 'VI'
E------------------------------------------------------

Back to Riff1 but only play twice (the 'I' again)

Riff 3
E-----------------------------------------------------
B-----------------------------------------------------
G-----------------------------------------------------
D-----7-7-6-6-5-5-6-6-(Once)-------------------
A-----5-5-5-5-5-5-5-5---------------------------- Thats your 'V7'
E------------------------------------------------------

Back to Riff2 played once (the 'VI')
Back to Riff1 played twice (OR... Play Riff 1 once and Riff 3 once - which is what 'WayOutThere' said if you were going to repeat)

here you can see there are 8 notes in each bar. The four BEATS to a bar is a timing thing. So i am using 2 notes per beat.