So, here goes... I have to come up with a melody for a progression consisting of D and the notes A F G# D E. I have no idea what to call the second chord, and am looking for an appropriate scale to write a vocal melody. As to confirming my suspicion, can I think of the chord progression Dm FMaj7 C G to be in the key of F? IOW, a melody played in F would work out well? Thanks for the help. I'm learning that I know enough to know I don't know enough...
Yes F will work with one clash, the G chord should be a Gm chord to fit within the key of F. You are on the right track. Always helps to start any "what if" by having all your notes in one scale and all your chords within the key made from that scale. I found this to be a great help.
Chords In The Key Of F
The rules of harmony are not all that complicated. The melody line and the chord line need to share some like notes. How many like notes? One per measure gets the job done - that is why just roots work. Two would be better and three per measure probably are not necessary as one got you harmonization.
If you start with chords the chord's pentatonic scale is a good candidate for your melody notes as the chord's pentatonic scale will give you three chord tones and two safe passing notes. The three chord tones gets the harmony and the two passing notes add flavor.
If you start with the melody the chords you put under your melody have two jobs. Movement and harmony. Harmony is achieved with the sharing of like notes and movement is achieved by moving the lyrics (song verse, phrase, whatever) from I rest to IV tension to V7 climax and then back to I for rest. I used the ole I-IV-V7-I as an example, the chord progression could move in many ways, ii-V7-I for example. Rest, tension, climax and then resolution back to rest is a safe movement structure as two of them will move a four line verse from rest and back to rest very well, i.e. one V-I cadence in the first two lines and then another V-I in the last two lines of the four line verse.
Harmony is achieved with the sharing of like notes - in the melody and chord line, i.e. treble and bass clef. This sharing of like notes flows through out music; it's how music wants to proceed.
Recapping: If you start with the melody you should have
a chord under the melody that has some of the melody notes in it's make up. If you start with the chord progression your melody should have some of the active chord's notes in the melody that is active over that harmonizing chord. If the melody moves on to notes that are not found in the old harmonizing chord, yep, its time to change chords.
It's a balancing act. Have fun.