Some of those who have collaborated with Piper over the years.

Lauren Adler, Anna Aronson, Alton Alburo, Lily Ali-Oshatz, Yoko Akasha, Jody Alperin, Jeremy Amar, Virginia Vetisian, David Bachman, Kesh Baggan, Matt Barbot, Tessa Barlow Ochshorn, Ezra Barnes, Alice Barrett, Doug Barron, Todd Bartels, Jessica Bates, Mary Baynard, Joe Bellino, Claudia Berring Elaine Bianchi, Sarah Ziegler Blair, Emily Bodkin, Matthew Bondy, Art Bonnano, Matt Bourne, Jordan Boughrum, Shane Breaux,  Justin Ivan Brown, Michael Buffer, Nick Calafiore, Caitlyn Calfas, Owen Campbell, Tobias Campbell, Chris Cariker, Sam Caravaglia, Deborah Carlson, Nic Casaula, Nick Chacon, Diane Chen, Zoë Cheswick, John Chilemi, Kathleen Choe,  Angela Cristantello, Andrew Christian, Eric Christian, Francesca Choy-Kee, Jacob Cohen, Sean Coughlin, Lynn Craig, Melinda Craig, Ashton Crosby, Vicky Finney Crouch, Gilbert Cruz, Jonathan Cruz, Karen Curlee, Kelley Curran, Ricky Dain Jones, Jennifer Damiano, Sam Dash, Nora Dellafera, Connor Delves, Melissa Diaz, Amelia Drezinski, Laura Dillman, Ashley Disciullo, Carolina Do, Caleb Donahoe, Ilana Dogim, Elizabeth Doyle, Marielle Duke, Molly Dunn, Rob Dunn, Erin Edelle, Sarah Edkins,  CJ Ehrlich, Rohana Elias Reyes, Beth Wren Elliott, Took Enlow, Ilan Eskanazi, Dallas Estes, Emily Feldman, Lauren Fajardo, Richard Fitzgerald, Tim Fitzsimons, Vasile Flutur, Ed Fohzo, Duncan Forbes, Declan Ford, Alex Fox, Ellie Frances, Tammuz Frankel, Alison Friedland, Shanara Gabrielle, Mark A. Galinovsky, Lana Gallo, Raul Garcia, Edi Mue Gathegi, Cara Geser, Joey Giambatista, Julie Gibson, Dylan Gilbert, Courtney Gilly, Mikey Giordano, Sam Given, Darrell Glasgow, Josh Gleb, Bettina Goolsby, Glenn Gordon, Nicholas Gossett, Lindsey Michelle Gradwohl, Sean Grady, Adrian Greensmith, Cody Grey, Sam Jay Gold, William Growney, Yangchen Gruben, Lou Gruber, Nick Guastella, Meredith Hackett, Haejin Han, Jan Leslie Harding, Mikey Harris, Mickey Zale Heller, Marcie Henderson, Su Hendrickson, Jessica Hester, Celeste Hines, Thomas Hoagland, Hal Hobson, Maeve Hogan, Zac Hoogendyk, Kumi Ishizawa, Dan Jacobson, Emily Janes, Jennifer Johannes,  Meghan E. Jones, Melanie Jones, Mina Jones, Sheila Joon, Joe Joyce, Jordan Kaplan, Hannah Karpenko, Dede Kavanaugh, Eiko Kawashima, Hannah Kiem, Garrett Kim, Jennifer Kipley, Lily Kleess, Kelly Blaze Klotz, Alex Knox, Katie Koster, Artem Kreimer, Janelle Lawrence, Samantha Leeds, Fenton Li, Mollie Lief, Tim Ling, Brandon Looney, Rachel McAlinn, Dionne McCalin-McFreeney, Annie McCoy, Jessie Medofer, Donovan Mendlovitz,  Maeve Mollaghan, Annie Montgomery, JK Musser, Clara Napolitano, Jack O’Brien, Michael Odofin, Robert Osbourne, Jason Pacella, Katie Palmer, Wendy Peace, Matt Petrick, Laura Parker, Rob Parker, Gina S. Pemberton, Alissa Laderer, Joe Laureiro, Linnea Larsdotter, Adam LeBow, Carl Louis, Jessica Lorenz Phillips, Will Lucas, Matt Luceno, Myles Angus MacVane, Allison Maldonado, Alec Mansky, Jonathan Marks, Jeremy Mather, JP Matthews, Tracy McAllister, Annie McCoy, Matthew McGloin, Erica McLaughlin, Dan McMahon, Hannah Jane McMurray, Donovan Mendelovitz, James Mendes, Corey Michner, David A. Miller, Annie Montgomery, Sean Moran, Laura Mulholland, Brandon Murphy, Mark Nassar, Paul Nicholas, Shannon Noecker, Christopher Nolan, Eliora Noetzel, Anne Marie Norberto, Aaron Novak, Dana O’Brien, Jack O’Brien, Masataka Odaki, Shawn Orbin, Megan Ort, Teddy Ostrow,  Jay Paranada, Norman Payne, Wendy Peace, Robyn Pearl, Arlene Penn, Matt Petrick, Will Petre, Tommy Philp, Sean Phillips, MaryAnne Piccolo, Lisa Pines, Thomas Piper, Jodie Porcelli, Benjamin Posner, Eric Potempa, Sebastian Quinn, Jossica Scott Raker, Jossica Ramin, Rachel Rear, Liz Rebert, Kati Rediger, Sally Regan, Jeremy Risch, Matthew Rini, Brandi Rhome, Marcy Richardson, Jamie Roach, Lucy Roslyn, Emma Rothstein, Cecelia Rubino, Kyle Runestad, Alison Ryan, Caroline Ryburn, Michael Saarella, Nikkole Salter, Adam Samtur, Saddiq Saunderson, Kim Sava, Elizabeth Sciacca, Will Schnurr, Rosa Schneider, Andrew Schoomaker, Hannah D. Scott, Melissa Scott-Luib, Lisanne Shaffer, Eliza Shea, Eva Sheehy-Moss, Christine Siegel, Peter Quentin Smith, Kristian Sorenson, M.X. Soto, Moggie Spear, Hillary Spector, Ashley Spivak, Jeff Sproul,  Lindsey Sproul, Matt Steiner, Eli Stiewig, Ali Stover, Michael Strong, Katherine E. Sulenski, Greg Sullivan, Philip Suracci, Lucas Tahiruzzaman Syed, Rachel Syzmanski, Tom Tammi, Robert Tarry, Ross Tatum, Ian Temple, Lia-Shae Tillett, Xalvador Tin-Bradbury, Lilia Trenkova, Fiore Terraciano, Francesco Tisch, Karen Tumulty, Chinaza Uche, Mia Van de Water, Patti Vecone, Melissa Vigado, Giovanni Villari, Olivia Virta, Arielle Vullo, Madeline Wall, Chloe Wakefield, John Wascavage, Case Watson, Maggie Weber,  Catherine Weingarten, Adam Weppler, Welker White, Amanda Whitefield, Joe Willens, Anne Windsland, Alice Winslow, Anne Windsland, Matthew Wise, Zachary Wobensmith, Jeffrey Lee Woods, Ryan Michele Healey Woods, Valerie Wright, Andrew Yee, Damian Young