Montréal GERMAN WALTZES AND LATIN PSALMS April 11 at 7:30 p.m. – Maison symphonique For the 10th edition of Opus concerts, Chœur Métropolitain presents Stravinsky’s Symphony of Psalms and Brahms’s Liebeslieder-Walzer and Neue Liebeslieder. Pianists Pierre McLean and Louise Pelletier will accompany the choir. www.orchestremetropolitain.com ARCHES: ARMENIA April 26 at 4 p.m. ; May 1, 2 and 9 at 7 p.m. – Various venues in Montreal Vocal ensemble Les Rugissants continues its Arches series exploring the history, music and architecture of important communities in Montreal. This series of concerts looks at the culture of Armenia with choral works by Sharafyan, Mansourian…