Mento focuses on witty, often bawdy, lyrical content and an ad hoc collection of acoustic instruments, normally banjo, small hand drums (e.g., bongos), and a bass lamellophone (known as a rumba box) derived from similar instruments found in Africa. A bamboo saxophone, fife, or homemade flute is sometimes included as well. Throughout the 1930s, Jamaican musicians often modeled their sound on popular calypso music imported from Trinidad. Consequently, early recordings sometimes refer to mento as "Jamaican calypso" or the more generic label "Jamaican folk song." Today, rural mento is regarded as the root of Jamaican popular music.