I am teaching myself to play the electric guitar and I have printed out various tabs to practice with. On one there is a 14 single note introduction but, I have heard versions played where some notes are single and some have been replaced with chords which seem to sound the same as the single notes but give the intro a far more dramatic and rounded effect. The first note is F# - G string 11th fret - but when I try to replace it with the chord of F# it just doesn't sound right. I understand using F# A# C# in building the chord but not where to actually start the chord to get a sound close enough to replace the single note. Perhaps I am getting this all wrong and F# is not the chord I actually need. Any advice would be appreciated.
I think you're looking for the concept of
Most cases of which I'm aware use diatonic (within the key) combinations of the notes of the major scale for the key in which you're playing.
So in your example, assuming the key is F#, the notes you have available to choose from (and remain diatonic) are:
Root | 2nd/9th | 3rd | 4th/11th | 5th | 6th/13th | 7th F# | G# | A# | B | C# | D# | F
A combination of your melody notes and 6ths (above and below the melody note) will sound something like
An example of 6ths would be a melody of
Mix in the 6ths and you get
I wish I could explain better, but I hope this will get you started.
One alternative is to test the chords where F# is
Knowing only one note of song, you should try all the 14 chords above.
But, if you know the key of song, we can reduce our trials to just 7 chords. For example, if the song is in the key of D, you should try the following chords:
This approach works for songs with simple melody and harmony.
Another way to beef-up a single-note line is to add a drone. If there's a note that's common to several chords in chart, you can play it once and have it ring over all the changes (by the distributive property :).
This adds the tension of suspense. Why didn't the note change? Oh no, when will it change??!
Then, Zing! It changes. Whew.
I often write songs this way. Melody, add drones, add third line to cinch the harmony. It's a much more horizontal way of building a song than starting with chords. FWIW.