SAN FRANCISCO — Depending on who you ask, Apple Inc.’s 2006 iTunes update was either a “significant enhancement” that gave users “amazing new features,” or it was a ruse created solely to feed the company’s monopoly over the MP3 music industry.

That critical distinction lies at the center of a trial commencing this week in Oakland federal court. It’s a battle 10 years in the making, which pits Apple’s legal team of Jones Day and Boies, Schiller & Flexner against a class of iPod buyers represented by Robbins Geller Rudman & Dowd. Barring a last-minute settlement, which neither side seems to think is likely, opening arguments begin Tuesday before U.S. District Judge Yvonne Gonzalez Rogers.