Instances rhymes with:
distances, substances, distances, sentences, substances, alliances, ambulances, appearances, appliances, audience's, audiences, balances, condolences, conferences, confidence's, distances, disturbances, entrances, evidences, fragrances, grievances, indulgences, performances, prominences, protuberances, provinces, resemblances, sciences, sentences, sequences, substances
Instances sounds like:
immunizations, incidence, incidences, inciting, ingesting, injecting, injections, insistence, insisting, instance, instituting, institution's, institutions, institutions'