The Amazon basin is bounded by the Guiana Highlands to the north and the Brazilian Highlands to the south. The Amazon River, which rises in the Andes Mountains at the west of the basin, is usually considered to be the second longest river in the world. However, a team of Brazilian scientists claim that the Amazon is the longest river in the world.
Singing is the act of producing musical sounds with the voice, and augments regular speech by the use of sustained tonality, rhythm, and a variety of vocal techniques. A person who sings is called a singer or vocalist. Singers perform music (arias, recitatives, songs, etc.) that can be sung with or without accompaniment by musical instruments. Singing is often done in an ensemble of musicians, such as a choir of singers or a band of instrumentalists.
1 Madonna, a title for Mary, mother of Jesus, a religious figure in Christianity and Islam.  Madonna (entertainer) (born 1958), American singer-songwriter and producer.