And I'm kinda wondering what key I'm in in this arpeggio. Anyone help me please?


I'm thinking E something. Could someone give me the exact key I'm in? I'd like to make a song out of this. Thankyouuuuuuuuu
How can you tell that it is in E major? F#, C#, D#, and G# are not present in the riff, which is why I am asking. Please explain, I'd like to learn.
F# = 7th fret B string
C# = 9th fret low E string
D# = 8th fret G string

There isn't a G# which makes it slightly ambiguous, but the E B D# signals a major tonality. also assuming this bar repeats, you have a V-I cadence (B-E)