yes, i meant shifting up one fret towards the bridge. thanks for your replies... to make a long story short, i needed to know because i had this riff i made up and i was trying to turn it into a 2-guitar harmony, so i first had to figure out what scale/mode it fit in.. and the phrygian shape worked.

let's say that i had a completely improvised riff and i wanted to harmonize it, but it didn't happen to fit into any ascertainable mode.. is there any other way? i mean how could you calculate, say, 3rds if you didn't know what scale/mode you were in??