SaraO said:

Yep, Oliver's right. It is played as if there is one beat per measure at 50 bpm. But it's ok if you're really counting 1-2-3 in your head.

Oliver said:

Don't bet your money but I think that means that a dotted half note (one measure) would equal one beat but we know that it is really 3 beats per measure at 3/4 time signature.  So us regular people would play 50 = 150 beats per minute or a factor 3.   The metronome can be set for 150 bpm and all is well.

I'm sure there is a very good reason for all this confusion but I can't imagine what that is (?)   (Must be a Baroque thing)

one question that repeats many others' question:

The tempo is one dotted half note = 1 half note, I got that part.

After practicing several times on the Christmas project this week at 50bpm and when the FM suggested to practice at 60bpm, I tried to switch to 60bpm. Then, remembering what the fiddlerman and Oliver had said, "set the metronome to 150 bpm," that confused me.

Below is my understanding:

If the required tempo is 60bpm, I need to set it at 180 bpm, that means the metronome would beep 3 times for each dotted half note. The time signature would be 3/4.

but if I set it at 4/4 60bpm (since each four bars equals one bar), that means I have 1 beat per measure (d. = 1 quater note) and my metronome would beep once for each dotted half note.

Am I confusing more people or am i making it clearer?  

Fiddlerman said:

I don't think that you are confusing anyone but If the metronome can be set for 1 @ 60 bpm instead of 4/4 it would make even more sense.

However, if I set it at 4/4 each first note would be emphasized to indicate that it is the first note of each measure (or in this case, it would be the first note of every four measures).