Just wondering if you could explain what diminished chords are, and their usage in guitar playing? I keep hearing people talk about them, and I'd like to understand more about how I can implement them into my practicing?
Carlos a diminished chord is just a chord built from the intervals:
1 b3 b5 ( bb7) if you want a dim7
You need to learn the major scale if you haven't already to apply these intervals in order to understand what they mean.
There's no exact way of using them as music cannot have fixed rules. That being said in diatonic harmony (normal keys) dim7 chords are nearly always used as chromatic passing chords. That means just fill the gap between 2 normal key chords.
If you take the key of C you have the chords
C, Dm, Em, F, G, Am, Bm7b5
So lets say you have a progression that does this
C, Dm, G, C
You could fill in with a diminished chord by using the chromatic step between 2 of the notes.
For example C, C#, D
To turn that into chords that harmonize we would play this
C, C#dim7, Dm So that progression I said earlier would become
C, C#dim7, Dm, G, C
Another common method of use is to use it after a IV chord when it's about to return to the I chord.