I want to produce a broad italic stroke but don't want a nib so crisp it will be hard to write with.
Judging from http://www.fountainpennetwork.com/forum/in...showtopic=12423, the 3776 is spot on. But I'm curious if anyone can compare this to the Custom 74 music.

Can't compare, but the Platinum music nib I have is not a sharp cornered/italic nib. Nice and smooth, and has been perfection out of the box.
gary

I have both pens and have used the Pilot extensively. Being a lefty is not easy and, it seems incongruous someone has never attempted to design a left-handed fountain pen. Yes, the Platinum is, in some regard, smoother and it might be slightly easier for me to grip. For me, the Pilot has been the only MUSIC nibbed pen I could use every day with my unique syle of handwriting.

If possible, try writing with both. There are a number of pen shows coming up this spring and if one is nearby see if any are available. Check out other brands too, including Sailor.

I have both, and while I love Pilot nibs, my music nib doesn't seem to have the line variation of the Platinum.

I have both, and I agree with zenshrink -- the Pilot music nib is smoother, but the Platinum offers more line variation for music composition. So for regular writing and signatures, I'm more likely to reach for the Pilot music nib. If I'm composing music and don't want to fuss too much about the angle I'm holding a pen, I'll reach for the Platinum music nib. Hope that helps.