I'm lost...

Okay, I've managed to come up with a pretty cool sounding riff, but I have no idea what Mode/scale I'm playing out of, which in turn makes it hard to do any sort of fill/solo that sounds musically correct!
I'm playing the chords G5, A#5, C5, and C#5. I've tried the pentatonic blues scale, but I don't think that I'm playing out of the right key with it. Please help...

try penatonic minor in c, g, or d. thats my thoughts condsidering most of those notes are on pentatonic minor c. just remember going on scales is good but someitmes they can tie you down and hold you back.

music theroy should be considered guidelines not laws.

well if your playing them in a straight ascending order there is no doubt your in C# progression-iii-IV-VII-I. So if you want minor pentatonic it's B but you can do a more bluesy thing and do C# minor but you could do G minor at parts. that just the problem with using fifths there just very neutral and can go hundred different ways. But harmonically you could sub Cb5 for a beat then into C5 to the tonic C#5 for a nice chromatic and that works no matter how you spin it.

Thanks guys!
@highonbodominflames
I beleive the same thing about theory, but I would like to know what I'm playing out of so I can make it sound close.

You are playing in a mode of Ab major

well I like to take the easy way out and just play the scale over whatever chord I start with for example it starts with G and

I play a G pentatonic, minor, harmonic minor, blues, etc I tried it so it seems alright.

i **ed up. first my roman numerals it's the fifth not the fourth so V instead of IV I typed it quick and didn't revise. and it's not VII to I it's vi to bVII. So it's c minor or Eb minor for bluesy. that goes to show not to do things real fast and think for a sec i just glanced and went OK. but when i looked at it again i was like Oh **. so it's progress is -iii-V-vi-bVII- you might want to resolve it to Eb but I'm going to guess and say you like the tension. so i'm sorry for being a dumbass

Edit-- see how long it takes to me to type(neither jeff nor league where there) I like Ab better so go with jeff and if you do go that way I'm going to guess G minor won't work don't have my guitar or anything. actually i don't like starting with a diminished so I'm going back to Eb

Thanks again, I'll go try it out now.

i think the best answer to this question is the chords to scales button on this site. then you can pick the scale(s) you can use...

I used the tool, and found out that it is in A# Minor Bepop...interesting scale. Plus me and my band now have a song out of it, minus the lyrics, were still instrumetal because of the lack of a vocalist.