Is it okay to write discontinued extracurriculars?

I started playing the cello in fourth grade and since then I’ve passed CM Level 4 and 7 with honors and 8 without. I was part of the CSUN Youth Philharmonic, another Honors Orchestra, and the orchestra at my church. However, I stopped playing the cello in sophomore year…

is it still okay to write cello as one of my extracurriculars?

Sure for Freshman and Sophomore years.

Agreed.