Two distinct cultures are represented in this series of songs. The Yuma and Cocopa belong to a group of tribes known as the Yuman, whose early home was the valley of the Colorado River. On either side of the river are sandy stretches, high mesa rims and barren mountains, while beyond is an expanse of arid desert. This geographical region shut in the tribes of the Colorado River and made them a unit, so that their culture, or civilization, is different from that of the Pueblo or the tribes of California. This is seen in the form of their melodies, while the words of the songs often mention the crossing of high mountains. The Yaqui are the principal members of the Piman family of tribes living chiefly in Sonora and Sinaloa, Mexico. Certain groups of these Indians live in Arizona and carry on their old customs but are not enrolled as United States Indians. The study of these interesting tribes was made in connection with the writer's research in Indian music for the Bureau of American Ethnology of the Smithsonian Institution,* in 1922.
The Yuma Reservation is on the California side of the Colorado River, opposite the town of Yuma in Arizona. The United States Indian Agency and School are on a high promontory overlooking the river and are on the site of Fort Yuma which was established after California was acquired by the United States. The Yuma Indians were living in the region at the time but offered no resistance to the coming of the white man. The Cocopa live south of the Yuma, on the Colorado River, and the Mohave, the third member of the group, live above the Yuma on the river. The Mohave were included, to some extent, in the regional study but on none of their songs are in the present series. The river civilization comes to a sudden stop with the Mohave, and above their country is the Eldorado Canyon, a bend of the river, and vast gorge that culminates in the Grand Canyon.
The Yuma and Mohave songs were recorded near the Agency. In order to secure the Cocopa songs it was necessary to go to a small Cocopa village near the town of Somerton, in the extreme southwestern portion of Arizona. A few Cocopa from Mexico live in this village but are not enrolled as United States Indians. The Government maintains a day school for the children but since the school was not in session, it was possible to obtain living quarters and a place to record songs. It was necessary to take two interpreters from Yuma, as none was available who could speak English, Yum and Cocopa. Accordingly, Luke Homer went to translate English in Yuma, as none was available who could speak English, Yuma and Cocopa. Accordingly, Luke Homer went to translate English into Yuma and Nelson Rainbow translated the Yuma into Cocopa. Homer had interpreted during the recording of the Yuma songs and was familiar with the writer's method of work, and Rainbow had recorded two songs, so he knew what was expected from a singer. Throughout this difficult trip the writer had the companionship of her sister, Margaret Densmore.
The Yaqui songs were recorded at Guadalupe Village, not far from Phoenix, Arizona. I went to this small village, from Phoenix, almost daily during the week preceding Easter, 1922, and witnessed the native celebration of holy week. On the day before Easter a performance was enacted in which the Deer dance was an important feature. A portion of the songs were recorded the day after Easter by Juan Ariwares who led the dance, and several are included in the present series. Two other Yaqui recorded their songs, which show Mexican influence.
More than 160 Yuman and Yaqui songs were recorded but only 130 were transcribed. The remainder were studied and found to contain the same peculiarities. The most important songs of both groups are in cycles, some with dancing and some without dancing. Such cycles of songs embody and preserve the traditions of the tribes.
A peculiar musical custom was found among the Yuma, Cocopa and Yaqui which has not been noted elsewhere. This custom consisted in a brief pause between the first and second periods, or sections, of the melody. The singers said there was no prescribed length of this pause and in the renditions it corresponds to only a few units of the tempo. In these songs the first melodic period is long and its phrases are sometimes repeated in irregular order. The second period begins in a different rhythm and is short, often containing tones that do not occur in the first period. This peculiarity occurs in the following songs of this series - A1 Yuma), A9, A10 (Yaqui); and A11, A12, A13, A14 (Cocopa).

* Densmore, Frances. Yuman and Yaqui Music, Bull. 110, Bur. Amer. Ethnol. 1932