Altfest rhymes with:
grundfest, manifest, slugfest, accessed, alkahest, armrest, backrest, bucharest, budapest, canwest, dataquest, envirotest, fieldcrest, finevest, fininvest, goldcrest, grundfest, hardpressed, headrest, healthvest, holmquest, incest, inquest, manifest, marquest, megaquest, outguessed, protest, ridgecrest, sealtest, seaquest, silvercrest, skywest, slugfest, unprocessed