Originally Posted by: Kasperow
Is there any real difference between improvising over Chords, Riffs and Arpeggios?

Yes, but it's more a matter of timbre & texture than keys, scales or chord progressions, note choice, etc.

No matter what style of music or what technique you are using when you improvise, you will be confronted with the same choices & decisions about keys, scales, chord progressions, etc.

Let's say you start with this basic chord progression.

C (I) - Am (vi) - Dm (ii) - G (V)

You can play those chords as fingerpicked arpeggios on an acoustic.
You can play those chords on a clean electric with a choppy staccato rhythm.
You can play those chords as diad riffs with a ultra-high gain humbucker guitar tone.

But the underlying information is the same. You've only changed the timbre & texture. Doesn't matter what tone, rhythms or guitar you use: it's still just I-vi-ii-V in C major.

Now what does change is the timbre. Those three approaches are going to sounds radically different from each other. Likewise, your approach to improvising, soloing or playing a melody along with those chords is going to be different depending upon which one you are playing with.

So, this is more a matter of becoming familiar with different aesthetic approaches, genres & styles. You have to experiment a lot with different guitars, amps, tones, styles while using the same ideas to see which matches best in any given context.

Jim Croce, Eric Clapton, Edward Van Halen all use the same 12 notes. :) They all only have access to the same basic raw materials of music: notes, scales, chords, keys, chord progressions.

Regarding the precise technicalities, you have to be aware of what chord, key or scale is being played, implied or suggested at any given time.

Obviously riffs can be played much differently than strumming straight full chords. But the same principles apply: your lead licks & lines have to be integrated with whatever is happening in the music at the same time.

If a chord progression is played by using arpeggios, then that rhythm part is going to be very busy with the chord tones spread out in time. You are going to have to find a way to play complementary & not just clutter things up rhythmically.

If a chord progression is more of just a riff in a certain scale or key, then you usually have a little more freedom, but you still have to consider what notes, scale or key the riff is using, implying or suggesting so you know which notes you can also use to make an integrated sound.

Broad topic, great question! :)

If you can post you riffs (audio or tab) I can give you some specific examples to try!