Saturday: 5:15 p.m. Heritage; Sunday: noon at Railroad with The Bronx New Heaven Shout Band, 4:15 p.m. Heritage

Robert Turner and the Silver Hearts Gospel Singers of Indianapolis have been performing gospel music for more than 40 years. Though its membership has changed, the group has held to the same spirited message and high standard of performance.

Despite the popularity of African-American gospel music and its influence on American popular music, it is a comparably recent music phenomenon. Rooted in religious songs, shape-note songs, spirituals, blues and ragtime, gospel emerged early in the 20th century. The term gospel music, in its most general application, refers to any religious music, regardless of age or origin. Less broadly, gospel refers to an innovative, popular style of music combining secular forms, particularly ragtime and blues, with religious texts.

Composed, modern black gospel music became an important style during the 1930s. In the wake of the great migration of rural Southern blacks northward in the early 20th century, gospel pioneers such as C.A. Tindley of Philadelphia, Thomas Dorsey of Chicago and W. Brewster of Memphis wrote music that combined elements of European choral singing and harmony with the more African preferences for alternation between lead singer and group response, vocal devices associated with early blues and jazz.

The music and language of early gospel songwriters, the use of primary chords, standardized chord progression, metaphorical language and frequent Bible allusions, coupled with music that encouraged participation and improvisation. By the mid-1930s, the appeal of gospel music within black culture was evident, and it soon was embraced by commercial record companies.

In the decade after 1945, the popularity of groups such as the Spirit of Memphis, Alex Bradford, the Soul Stirrers, Queen C. Anderson, Sallie Martin and the Famous Blue Jay Singers grew. Dozens of professional and semiprofessional groups appeared on programs throughout the country and recorded for an expanding network of local and regional companies.

A thriving gospel concert circuit developed. Groups dressed in matching outfits and added instruments. By the 1950s, gospel concerts were taking place throughout small-town America, and touring groups commanded high fees and played at some of the largest venues in the country.

It was this period that inspired Robert Turner’s style of gospel. Besides exhibiting talent from a young age, Turner had the added advantage of coming from Indianapolis, one of the country’s main gospel centers. Turner began singing in church at age 4 and joined his church’s traveling choir at 10. After being exposed to the new piano-driven gospel style at a Clara Ward Singers concert, Turner formed the Silver Hearts Gospel Singers of Indianapolis in 1960. He was only 15 years old.

Since that time, gospel has taken many new turns, but the Turner group has stuck to the basics. It is an Indianapolis institution, performing at churches, church reunions and community gatherings. The group organizes a 40-year-old annual citywide Gospel Extravaganza, and Turner himself is host of a weekday and Sunday morning gospel radio show. The group today is composed of Turner (vocals), Tony Carpenter (keyboard), David Taylor (drums), Angelo Bridges (keyboard), Joseph Duncan Jr. (bass), Deborah Barnett (vocals), Carmella Hardy (vocals), Linda Bush (vocals) and Diana Brooley (vocals).