A few years ago a friend and I realized that we both loved singing but didn't do much of it. So we started a weekly a capella group with just four members. After a year we started inviting other people to join. We didn't insist on musical experience — in fact some of our members had never sung before. Now the group has ballooned to around 15 or 20 people. [...] Well here's what we do in an evening: We get some drinks, some snacks, some sheets of lyrics and a strict starting time. We warm up a bit first. The critical thing turns out to be the choice of songs. The songs that seem to work best are those based around the basic chords of blues and rock and country music. You want songs that are word-rich, but also vowel-rich[.]