Chris Willman Music WriterWhen the Nashville chapter of the Recording Academy held its annual pre-Grammys celebration for Tennessee-based nominees in early March, one of those contenders, Yola, filed a report from the party on Instagram. “The vibes were strong,” she wrote, “and so was the melanin!”Looking at the nominations in the country, folk and American roots categories, it was clear what the people of color in the chapter had to celebrate — and the Black women most of all.