I have a clean song I am woking on. It was partly inspired by Black Stallion by Jason Becker & Marty Friedman.

The chord progression is E B C# A

I am not sure what E it is because the G string is not played, and the B is neither major nor minor.

What key is this in? If i want to change mood in the song, and resolve it back again, what are the relative keys I could use? The song is meant to sound kinda like a love song with a sense of sadness or sorrow about it, but not with a minor, dark feel.

Any help is appreciated. Thanks in advance