Violist's rhymes with:
violists, violists, violists, analysts, anti-federalists, ballasts, capitalists, catalysts, finalists, herbalist's, herbalists, herbalists', institutionalists, journalists, nihilists, novelists, socialists, specialists, symbolists, televangelists, traditionalists, ultranationalist's, ultranationalists, violists
Violist's sounds like:
valujet's, velocities, violists