Bolivian folk music has been subject to very little changes due to it's geographic isolation. Pre-hispanic instruments such as the variants of the siku and quena are are still used today. Bolivian musical traditions have evolved from a series of pre-inca, inca, spanish amazonian and even african influences. The sound of andean music, due to the cold and vast altiplano is, appropriately sober and introspective in contrast to the sound of the more warmer zones, that with it's variety of musical instruments, offers more vibrant and colorful tones. Even though bolivian music was exclusively instrumental, the trend towards popularization has inspired the addition of magnificent vocal melodies.