The easiest options are to use an E7 or G#dim7 to get to A, as these chords contain A's leading tone G#, but using two or more chords can make for a more convincing modulation. In this case, you could set up a ii > V > i to A minor. From a C tonality, drop in a Bm7 (Bm7b5, depending on if you want an F or F#) > E7 >Am.
Can you switch modes in music?
Every time you play a different chord in a song you are changing modes. Changing chords does not change the mode of the music. Jazz theorists like to talk about using different modes for improvising over chord changes, but that doesn't necessarily change the mode of the music.
What chords work with modes?
Major chords follow the formula 1-3-5-7. Both Ionian and Lydian modes contain these notes; therefore either mode can be used. Minor chords follow the formula 1-b3-5-b7. Dorian, phrygian, and aeolian all contain that formula, therefore any one of them can be played.
How do you modulate between chords?
How to apply (diatonic or altered) common chord modulation:
- Establish a tonal center (home key) through a progression, cadence, or static harmony.
- When you are ready to modulate, use your diatonic/altered common chord to pivot into destination key.
- Confirm the new key with a cadence.