Tallis:Spem in Alium
This was the Tallis Scholars' first recording devoted to their namesake  composer--and it remains one of the best Tallis discs available. Its centerpiece  is, of course, the famousSpem in aliumfor eight five-voice choirs. This  is a spectacular piece, with voices entering one by one and leading to a sudden,  crashing entry for all eight choirs; the choirs then toss pealing phrases back  and forth (listen with headphones!) and finish with a monumental 40-voice chord.  Other treats include the popular Pentecost motetLoquebantur variis  linguis,two beautiful settings of the prayerSalvator mundi,and the  20-minute votive antiphonGaude gloriosa,which has intricate imitative  passages for three to four soloists alternating with powerful writing for full  choir.--Matthew Westphal