Harmoniser… Twin-guitar lines
Need another guitarist? You might just get away with a harmoniser
Three-part harmony lines? You can do that with a pitch shifter or harmoniser effect. Get your Maidenstyle lead lines and Thin Lizzy twin-guitar licks on by setting your harmoniser effect to a 3rd, 5th or a combination of both intervals.
If your pedal has the option to select major or minor, along with the key, you can make sure that it stays within the scale as you run up and down. If the song includes ‘out of key’ notes, simply switch your pedal off during the more troublesome moments.