Hierarchical clustering optimizes the tradeoff between compositionality and expressivity of task structures in reinforcement learning

A hallmark of human intelligence is our ability to compositionally generalise: that is, to recompose familiar knowledge components in novel ways to solve new problems. For instance, a talented musician can conceivably transfer her knowledge of flute fingerings and guitar songs to play guitar music on a piccolo for the first time. Yet there are also instances where it can be helpful to learn and transfer not just individual task components, but entire structures or substructures, particularly whenever these recur in natural tasks (e.g., in bluegrass music one might transfer the joint structure of finger movements and musical scales from one stringed instrument to another). Prior theoretical work has explored how agents can learn and generalize task components or entire latent structures, but a satisfactory account for how a single agent can simultaneously satisfy the two competing demands is still lacking. Here, we propose a hierarchical model-based agent that learns and transfers individual task components as well as entire structures by inferring both through a non-parametric Bayesian model of the task. It maintains a factorised representation of task components through a hierarchical Dirichlet process, but it also represents different possible covariances between these components through a standard Dirichlet process. We validate our approach on a variety of navigation tasks covering a wide range of statistical correlations between task components and show that this hierarchical framework can also be applied to improve generalisation and transfer in hierarchical tasks with goal/subgoal structures.

Bobby Osborne Remembers How It Was

In an interview conducted by the chairman of the International Bluegrass Music Association, Bobby Osborne tells how he grew up in Thousandsticks, Kentucky in the 1930s. In 1942 his family moved to Dayton, Ohio. Bobby and his brother Sonny played music, and while teenagers appeared on Middletown’s WPFB Jamboree. Bobby earned a Purple Heart as a Marine in Korea. In the early and mid-1950s the Osborne Brothers played with Red Allen at bars in Dayton and at the Wheeling Jamboree, and recorded such bluegrass hits as “Once More” and “Ruby, Are You Mad.” At Antioch College in 1960 they played the first campus bluegrass concert in history. Doyle Wilburn arranged their Grand Ole Opry audition and a Decca contract with producer Owen Bradley.

Industrial Strength Bluegrass

In the twentieth century, hundreds of thousands of migrants seeking economic opportunities relocated from the Appalachian region to southwestern Ohio. They brought mountain and gospel music with them, as well as an openness to new sounds that were emerging in mid-century. Without access to capital, formal instruction, or mainstream media attention, a core of devoted musicians and entrepreneurs built an unrivaled radio, recording, and performance infrastructure for bluegrass music. Between 1947 and 1989, important careers were launched and the distinct artistry of bluegrass made during those years in Cincinnati, Dayton, Middletown, Hamilton, Springfield and environs—an area of approximately 250 square miles—had a permanent influence on American roots music. This work explores the history of southwestern Ohio’s Appalachian migration and the subsequent proliferation of bluegrass musicians, radio broadcasters, recording studios, record labels, bars, festivals, and sacred music. It also explores how following generations built upon that base, how bluegrass reached non-Appalachian participants, how bluegrass was used in public education and community development, and how distinctive musical qualities of bluegrass that flourished in the southwestern Ohio region influenced the worldwide development of the genre. First-person narratives of key figures are included as well as analytical essays by academic and independent scholars, along with suggestions for further reading and listening.

The Living Arts Center’s East Dayton Roots

Bluegrass thrived in 1960s and 1970s Dayton. From 1967 to 1977 the U.S. Department of Health, Education and Welfare and Dayton Board of Education funded professional artists instructing 400 students at the Living Arts Center. In 1975 the Hotmud Family began hosting a “song swap” for old-time and bluegrass music, as well as the live Country Music Jamboree on WYSO. Kathy Anderson, Al Turnbull and Jim Johnson recalled performers such as Arnold Cox, Van Kidwell, Wendell McCoy, Harold Staggs, Dorsey Harvey, Ron Thomason, Fred Hoskins, Bob Ferguson, Howard Brown, Dan Spires, Bill Lowe, Duffee brothers, Elzie and Danny Davis, Phyllis Tipton Moyer, Bill Stockwell, Mike Lilly, J.D. Crowe, Terry Tipton, Tom Duffee, Barb Kuhns, Linda Scutt, Doug Smith, and Al Turnbull.

Using My Bible for a Roadmap

Musicians, ministers, evangelical churches, music promoters, recording studios, and radio made southwestern Ohio an epicenter for sacred bluegrass. Worship services, revivals, homecomings, church concerts, WPFB’s Hymns from the Hills and WYSO’s Rise When the Rooster Crows played sacred bluegrass music. The Brown’s Ferry Four and King’s Sacred Quartet recorded at King. Shannon Grayson, Flatt and Scruggs, Jim and Jesse, Reno and Smiley, Sonny Osborne, Red Allen, the Stanley Brothers, Moore and Napier, and J.D. Jarvis also recorded in Cincinnati. Lillimae Haney Whitaker headed the Dixie Gospel-Aires. The Boys from Indiana, Joe Isaacs, and Larry Sparks had gospel releases. Pastors Kash Amburgy, Norm Livingston, and Lawrence Bishop promoted gospel singing. The Southwestern Ohio Bluegrass Music Heritage Project lists thirty-one other regional gospel artists at swohiobluegrass.com.

All the Way to the Fence

Broadcasting was significant to creating a bluegrass music market. Radio personalities reminded Appalachians of home with familiar music and colorful dialect. Live programs on Cincinnati’s WLW showcased early Appalachian musicians. WCKY disc jockeys Nelson King and Wayne Raney played bluegrass records in the 1940s and 1950s, while promoting Jimmie Skinner’s record sales outlets. Paul Braden founded Middletown’s WPFB in 1947, Braden and announcer Smokey Ward featured numerous future bluegrass stars on the WPFB Jamboree. Influential radio personality Tommy Sutton joined WPFB in the 1950s, and took the Osborne Brothers’ demo to Nashville. Paul “Moon” Mullins joined WPFB in 1964. His folksy manner, ad-lib commercials, and humorous stories made him a regional star. His son Joe Mullins keeps tradition alive on today’s Real Roots Radio Network.

Bluegrass Music and Urban Appalachian Identity in Cincinnati

Neighborhood cultural and political development in 1960s and 1970s Cincinnati coalesced around music, a positive expression of urban Appalachian culture. United Appalachian Cincinnati embraced folk-revival bluegrass and established new advocacy. Mike Maloney, Ernie Mynatt, and Stuart Faber helped Appalachians receive federal money via agencies addressing urban issues. Main Street Bible Center, Appalachian Identity Center, and the Appalachian Heritage Room were early manifestations. The Urban Appalachian Council emerged in 1974. Earl Taylor was lionized as the “authentic” bluegrass musician. After 1960, musicians honed their skills to his music at Ken-Mill Café. In the early 1970s the Katie Laur Band played in schools. Cincinnati’s Appalachian Festival—begun in 1970—highlighted positive aspects of mountain culture, including music and crafts.

Epilogue

When the International Bluegrass Music Association moved its World of Bluegrass festival to Raleigh in 2013, it seemed to acknowledge North Carolina’s under-appreciated role in bluegrass history -- even though Nashville partisans didn’t see things that way and sneered that Raleigh was undeserving. But the festival was a huge hit in Raleigh right out of the gate. The downtown setting, right by where Bill Monroe used to play in radio station WPTF’s studio in the 1930s, was even more appropriate.

She's A Country Girl All Right

Classically trained vocalist, songwriter, multi-instrumentalist, and 2017 MacArthur “Genius” Fellow Rhiannon Giddens has in recent years enjoyed increased visibility in the contemporary country music world. In 2016, she was a featured singer on Eric Church's top-ten country hit, “Kill a Word,” and she won the Steve Martin Prize for Excellence in Banjo and Bluegrass that same year. Giddens also had a recurring role as social worker Hanna Lee “Hallie” Jordan on the long-running musical drama Nashville in 2017 and 2018. While Giddens now enjoys a certain degree of acceptance in the country music world, she has not always felt included in the various largely white, contemporary American roots scenes. As such, she continues to speak out to audiences and the press about the erasure of African Americans from histories of string music, bluegrass, country, and other styles and forms of American roots music. Using Giddens's 2017 International Bluegrass Music Association (IBMA) keynote, and the Carolina Chocolate Drops' music video for the song “Country Girl” from 2012's Leaving Eden, I demonstrate that Giddens effectively reclaims American old-time string music and country culture as black, subverting historically inaccurate racialized notions of country music authenticity.