Question: What American bluegrass singer guest performs on an album by American country music singer Daryle Singletary?
Context: Straight from the Heart is the fifth studio album by American country music singer Daryle Singletary.  It was released on February 27, 2007 via Shanachie Records.  Like his last album, 2002's "That's Why I Sing This Way", this album is largely composed of cover songs, save for "I Still Sing This Way", which is an original song.  It and "Jesus & Bartenders" were both released as singles from this album, although both failed to chart.  As with his last covers album, this one includes several guest appearances. Daryle Bruce Singletary (born March 10, 1971) is an American country music singer.  Between 1995 and 1998, he recorded for Giant Records, for which he released three studio albums: "Daryle Singletary" in 1995, "All Because of You" in 1996 and "Ain't It the Truth" in 1998.  In the same timespan, Singletary entered the top 40 of the Hot Country Songs charts five times, reaching number two with "I Let Her Lie" and "Amen Kind of Love", and number four with "Too Much Fun". Now and Again is American country music singer Daryle Singletary.  It was released in 2000 via Koch Records.  The album includes six songs from his previous albums for Giant Records: "I Let Her Lie, "Too Much Fun" and "Would These Arms Be in Your Way" from "Daryle Singletary", "Amen Kind of Love" from "All Because of You", and "You Ain't Heard Nothing Yet" and "The Note" from "Ain't It the Truth".  It also includes four new tracks in "I've Thought of Everything", "Dumaflache", a cover of Savage Garden's "I Knew I Loved You", and the title track.  "I Knew I Loved You" and "I've Thought of Everything" were both released as singles, peaking at #55 and #70 on the U.S. country singles charts. That's Why I Sing This Way is the fourth studio album by American country music singer Daryle Singletary.  It was released on April 23, 2002 via Koch Records.  Except for its title track, the album is composed of cover songs. Two singles were released from it: the title track and a cover of Conway Twitty's 1980 Number One single "I'd Love to Lay You Down", which respectively reached #47 and #43 on the U.S. "Billboard" country singles charts.  The version of "I Never Go Around Mirrors" on this album was first recorded by Keith Whitley, Whitley had Shafer write the second verse heard here.  The album includes guest appearances from George Jones, Dwight Yoakam, Rhonda Vincent, John Wesley Ryles, Merle Haggard and Johnny Paycheck. Ain't It the Truth is the third studio album by American country music singer Daryle Singletary.  It was released in 1998 via Giant Records.  It was led off by the single "The Note" (previously recorded by Doug Supernaw on 1995's "You Still Got Me"), which peaked at #28 on the country singles charts that year.  The next two singles, "That's Where You're Wrong" and "My Baby's Lovin'" both missed Top 40, and by the end of the year, Singletary exited the label's roster.  "A Thing Called Love" was originally released by Jimmy Dean.  "The Note" was also Singletary's only entry on the "Billboard" Hot 100 chart, peaking at #90. All Because of You is the second album by American country music singer Daryle Singletary.  It was released on October 8, 1996 via Giant Records.  Although its lead-off single "Amen Kind of Love" reached #2 on the U.S. country singles charts, the next two singles ("The Used to Be's" and "Even the Wind") both missed Top 40.  The album was produced by David Malloy and James Stroud, who also produced Singletary's 1995 self-titled debut. "I'm Living Up to Her Low Expectations" is a debut song recorded by American country music artist Daryle Singletary.  It was released in April 1995 as the first single from the album "Daryle Singletary".  The song reached #39 on the "Billboard" Hot Country Singles & Tracks chart.  The song was written by Bob McDill and Tommy Rocco. Rhonda Lea Vincent (born July 13, 1962) is an American bluegrass singer, songwriter, and multi-instrumentalist.  In 2000, "The Wall Street Journal" proclaimed Vincent "the new Queen of Bluegrass". "I Let Her Lie" is a song written by Tim Johnson, and recorded by American country music artist Daryle Singletary.  It was released in July 1995 as the second single from the album "Daryle Singletary".  The song reached number 2 on the "Billboard" Hot Country Singles & Tracks chart. Daryle Singletary is the self-titled debut album of American country music singer Daryle Singletary.  It was released in 1995 (see 1995 in country music) via Giant Records Nashville.  The album includes four singles: "I'm Living Up to Her Low Expectations", "I Let Her Lie", "Too Much Fun" and "Workin' It Out", all of which charted on the "Billboard" country singles charts between 1995 and 1996.  Although "I Let Her Lie" and "Too Much Fun" were both Top 5 country hits, the album only peaked at #44 on Top Country Albums.
Answer: Rhonda Vincent