Question: Over which holiday weekend is the event at which the Purdue All-American Marching Band is the host band?

Context paragraphs:
Purdue All-American Marching Band: The Purdue "All-American" Marching Band (or AAMB) is the marching band of Purdue University and the main source of auxiliary entertainment for Purdue Boilermakers football games.  The AAMB is also the host band of the Indianapolis 500 race, having held the position since 1927.  The band has grown from an original 5 members to 389 members.  The three most distinctive features of the AAMB are the World's Largest Drum, the Purdue Golden Girl featured twirler, and the "Block P," the first marching band field formation created in 1907.

Band camp: A band camp typically refers to a high school, college, or university marching band summer camp.  Band camp is often mandatory for members of the band, and constitutes the majority of the preparation a marching band makes before its marching season (learning how to march, learning "sets" on the field, memorizing show songs).  A high school marching band may travel to a college or university for band camp for use of its facilities (dormitories, fieldhouses, fields) and services, or it may stay at the school.  The time at band camp is used for focused rehearsals and time for bonding between band members.The colorguard also learns and rehearses with the marching band.

Cavalier Marching Band: The Cavalier Marching Band (CMB) is the premier marching ensemble at the University of Virginia.  Under the direction of Dr. William E. Pease, the first full-time marching band director in University of Virginia history, the Cavalier Marching Band made its debut on September 11, 2004 after a considerable donation was made by University of Virginia benefactors Carl and Hunter Smith to found the band in 2003.  Currently in its eleventh season, the band is composed of over 330 of the University of Virginia's best and brightest student musicians, with representatives from over 80 different majors from all 7 of the undergraduate schools.  Whenever describing the composition of the members of the band, Pease typically states that almost none are music majors but almost a third hold leadership positions, thus emphasizing the virtue of student-self-governance, an ideal widely emphasized at the University of Virginia.  On September 2, 2011, the Cavalier Marching Band moved into the Hunter Smith Band Building within the College of Arts & Sciences.

University of Nebraska Cornhusker Marching Band: The University of Nebraska Cornhusker Marching Band (also known as the Marching Red or The Pride of All Nebraska) is the marching band of the University of Nebraska.  It performs at all home football games.  Founded in 1879, the Marching Red is one of the oldest and best-known collegiate marching bands in the United States.  The band consists of 300 students from over 60 different academic majors from across the campus.  Thanks to the success of the Husker football program, the Marching Red is also one of the most traveled bands in the country having participated in all of the major bowl games.  They have appeared multiple times at the Rose, Fiesta, Orange, Sugar, Cotton, Sun, and Alamo Bowls, and have made single appearances at the Bluebonnet, Liberty, Holiday, Citrus, Independence and Gator Bowls.  On November 19, 2011, the Cornhusker Marching Band performed at Michigan Stadium in front of the largest audience ever to watch the band.

Purdue Big Bass Drum: The Purdue Big Bass Drum is a percussion instrument played by the All-American Marching Band of Purdue University.  At a height of over ten feet (three meters) when the carriage is included, it is branded by Purdue as the "World's Largest Drum."  Since its inception, it has become a lasting symbol of the marching band as well as the university.  The drum can be seen at all home football games as well as parades, alumni rallies, the Indianapolis 500 Race, and many other special events.

Mustang Band: The Cal Poly Mustang Band, also known as The Pride of the Pacific, is the official marching band of California Polytechnic State University in the city of San Luis Obispo, California.  Although the band is not a competitive marching band they serve as a school spirit organization.  The band functions in two different forms throughout the year.  In the fall the band marches as The Mustang Marching Band and during Cal Poly's winter quarter they function as a pep band.  The band attends many athletic events during the year to encourage the school's athletic teams and audience support/involvement.  The marching band is well-known around campus as an exciting and spirited group that brings pep, passion, and tradition to every performance.  The marching band is conducted by three directors: Andrew McMahan (Director of Bands), Christopher Woodruff (Associate Director), and Len Kawamoto (Assistant Director).

Oregon State University Marching Band: With over 250 members, the Oregon State University Marching Band, ("OSUMB"), is the marching band of Oregon State University, known as the ""Spirit and Sound of OSU"."  It was founded in 1891 making it the oldest band in the Pac-12.  The Oregon State University Marching Band is the primary athletic band at Oregon State.  In addition to the Oregon State University Marching Band, other athletic bands include Basketball Band, Rhythm & Beavs, Rhythm & Beavs: Travel Band, the Away Game Pep Band (for select away games), Alumni Band (the band that covers any games occurring prior to the start of the school term), Gymnastics Band (the ensemble that performs at home gymnastic meets; this ensemble also include alumni members), and Bar Band (a small ensemble that tours local bars on the day before a home football game).  All band members are required to participate in marching band before they may be eligible to participate in any of the other bands Oregon State offers.

Indianapolis 500: The Indianapolis 500 is an automobile race held annually at Indianapolis Motor Speedway in Speedway, Indiana, an enclave suburb of Indianapolis, Indiana.  The event is held over Memorial Day weekend.  It is contested as part of the Verizon IndyCar Series, the top level of American Championship Car racing, an open-wheel formula colloquially known as "Indy Car Racing".  The name of the race is often shortened to Indy 500.

U.S. Army All-American Marching Band: The U.S. Army All-American Marching Band is a U.S. Army-sponsored civilian marching band competitively recruited from high school senior musicians early each December and dissolved the following month.

U.S. Army All-American Bowl: The U.S. Army All-American Bowl is a high school football all-American game.  Due to its distinction as "Military City USA" the bowl is held annually in San Antonio, Texas.  Currently played in the Alamodome, the game brings together 90 of the nation's top high school football players in an East versus West matchup.  In addition to the bowl game, there is the U.S. Army All-American Marching Band, which comprises 125 of the nation’s top high school marching musicians who perform during halftime of the U.S. Army All-American Bowl.  The game enjoys a worldwide audience thanks to broadcast partner NBC, and more than 40,000 in attendance every year.

Supporting paragraphs: Purdue All-American Marching Band Indianapolis 500
Answer: Memorial Day weekend