Mariachi in front of the plaza to flag down passing cars. In 2010, the government renovated the plaza to make it more tourist-friendly, adding new paving, gardens, police, security cameras, painted facades, and a museum dedicated to mariachi and tequila. Although mariachis can be hired in Mexico City over the phone or on the internet, many people still prefer to come to the plaza, hear the musicians and haggle over the price. About 2,500 mariachis hold union cards to work in the plaza, but as many as 4,000 may circulate through on a busy weekend. The size of a Mariachi group
Mariachi problems recruiting mariachi instructors as many of these do not have required teaching credentials. For this reason, schools often hire trained musicians from outside the mariachi tradition. Many traditional mariachis are concerned that standardization will lead to fossilization and restrict improvisation. Other innovations in the United States have been the incorporation of styles of artists such as Elvis Presley, Freddy Fender and Glenn Miller, as well as the heavy-metal Mariachi band Metalachi. Another is the encouragement of female mariachis including all-female Mariachi groups such as Mariachi Mujer 2000 and Mariachi Divas de Cindy Shea. Mariachi Mujer has performed with Mexican