The 'Romancero Gitano' (Gypsy Ballads) is a book of poems by Federico Garcia Lorca, published in 1928. It's made up of 18 ballads revolving around the topic of the gypsy life style, culture and customs. The ballads reflect the pains of the gypsy people who live in the margins of society and are constantly persecuted by the authorities, and the fight against them and their repressive laws.
The Romancero Gitano is Federico Garcia Lorca's most famous book od poems, and for this it's studied by everyone who wants to study Spanish. It's also the most bought book of Spanish poems, and many bands have used them as lyrics for their songs.