Question: Which Cracker album included  musical accompaniment by a band native to Boulder, Colorado?
Context: Musical Accompaniment for the End of the World (Songs for Two Pianos, Tactful Synths and Voice) is the fourth studio album by the Slovene duo Silence, scheduled to be released worldwide on April 14, 2012 — the 100th anniversary of the sinking of the RMS Titanic.  The recording of the prominent piano instrumentals was made at Vatroslav Lisinski Concert Hall in Zagreb, Croatia, on July 1, 2011, with Igor Vicentić and Sašo Vollmaier accompaniment. Native Window is the self-titled debut album of American progressive rock band Native Window.  It was released on June 23, 2009.  The tracks on the album are all original material composed by the members of the band.  The album came about soon after the band formed; it was because Steve Walsh, the lead singer for Kansas, would not write any new material.  Phil Ehart, Rich Williams, Billy Greer, and David Ragsdale got together to write new songs, and released them under the Native Window name. Microsoft Research Songsmith is a musical accompaniment application for Microsoft Windows, launched in early 2009.  Songsmith immediately generates a musical accompaniment after a voice is recorded.  The user can adjust tempo, genre (such as pop, R&B, hip-hop, rock, jazz, or reggae), and overall mood (e.g. to make it happy, sad, jazzy, etc.). O' Cracker Where Art Thou?  is a compilation album containing bluegrass versions of Cracker songs.  The songs are played by two members of Cracker, David Lowery and Johnny Hickman, with musical accompaniment by Leftover Salmon. Rapping (or rhyming, spitting, emceeing, MCing ) is a musical form of vocal delivery that incorporates "rhyme, rhythmic speech, and street vernacular", which is performed or chanted in a variety of ways, usually over a backbeat or musical accompaniment.  The components of rap include "content" (what is being said), "flow" (rhythm, rhyme), and "delivery" (cadence, tone).  Rap differs from spoken-word poetry in that rap is usually performed in time to an instrumental track.  Rap is often associated with, and is a primary ingredient of hip-hop music, but the origins of the phenomenon predate hip-hop culture.  The earliest precursor to the modern rap is the West African griot tradition, in which "oral historians", or "praise-singers", would disseminate oral traditions and genealogies, or use their formidable rhetorical techniques for gossip or to "praise or critique individuals."  Griot traditions connect to rap along a lineage of Black verbal reverence that goes back to ancient Egyptian practices, through James Brown interacting with the crowd and the band between songs, to Muhammad Ali's quick-witted verbal taunts and the palpitating poems of the Last Poets.  Therefore, rap lyrics and music are part of the "Black rhetorical continuum", and aim to reuse elements of past traditions while expanding upon them through "creative use of language and rhetorical styles and strategies.  The person credited with originating the style of "delivering rhymes over extensive music", that would become known as rap, was Harlem, New York native, Anthony "DJ Hollywood" Holloway. Oyilattam (Tamil: ஒயிலாட்டம் ; meaning: dance of grace) is a folk dance with origins in the Madurai region of Tamil Nadu.  The dance has its origins in southern Tamil Nadu and is primarily performed in Madurai district, Tirunelveli district and Tiruchirapalli district.  It was traditionally a dance where a few men would stand in a row and perform rhythmic steps to the musical accompaniment, with the number of dancers increasing; over the past ten years women have also started performing this dance.  Typically, the musical accompaniment is the Thavil and the performers have coloured handkerchiefs tied to their fingers and wear ankle bells.  Oyilattam is one of the folk arts identified for mainstreaming by the Tamil university.  Mainly Oyilattam is performed at village festivals.  It is basically describing the great epics like ramayana, mahabaratha and also lord muruga's history. The Numbskulls (aka HyperzombieNumbSkulls) were an influential acid house band from Boulder, Colorado in the early to mid-1980s.  Influenced by the Madchester style of music of The Stone Roses and Happy Mondays, as well as punk/new wave bands New Order and The Cure, the Numbskulls catalogue included whimsical lyrics juxtaposed against repetitive keyboards, trance-like drumming, melodic vocals and quirky punk guitar hooks.  They referred to their musical style as "danceable dirge".  The band was a four piece with band leader, Mike Harris Bacidore on keyboards, bass, and vocals, Mateo Juarez (Matthew Harris Sullivan) on lead guitar and vocals, Mike Tomich on guitars and vocals, and Scuz Roland (Don Adydan) on drums.  The Numbskulls were founded by Bacidore and Sullivan in Longmont, Colorado in 1983.  The band often dressed up in leisure suits and rubber masks, reggae attire, or as hippies and played under a variety of inane monikers, most notably "Happy World Beat" — thus, only their most rabid fans were aware of their true identity.  They enjoyed playing techno punk jams, an antithetical punk style whereby their songs would often last fifteen minutes or more and were a spontaneous combination of funk, punk, reggae, jazz, techno, and new wave.  The Madchester style to which their music is often associated was not yet popular in the United States, and as fervent followers, the Numbskulls ushered the era of ecstasy laden rave culture of the late eighties in the Boulder and Denver area of Colorado.  The band released several underground albums including "HyperzombieNumbSkuLLs" (1983), "Rubberface" (1984), "Big Bowel Movement" (1985), "Get in the Groove" (1985), and "Red Light" (1986). A workshop production is a form of theatrical performance, in which a play or musical is staged in a modest form which does not include some aspects of a full production.  For example, costumes, sets and musical accompaniment may be excluded, or may be included in a simpler form. "Moment of Surrender" is a song by rock band U2 and the third track on their 2009 album "No Line on the Horizon".  During the initial recording sessions for the album in 2007 in Fez, Morocco, the band wrote the song with producers Brian Eno and Daniel Lanois within a few hours.  Together, they recorded the song in a single take; Eno called the song's recording "the most amazing studio experience [he's] ever had".  According to him and Lanois, the track is the closest the band came to realising their original concept for the album of writing "future hymns".  The seven-minute song features gospel-like vocals in the chorus, along with a predominantly organ- and piano-based musical accompaniment.  Lyrically, the song is about a drug addict who is undergoing a crisis of faith. Leftover Salmon is a jam band from Boulder, Colorado, formed in 1989.  Their unique blend of bluegrass, rock, country, and Cajun/Zydeco, which the band calls "Polyethnic Cajun Slamgrass", has found favor with the jam band scene.  The band took a hiatus in 2005, and spent parts of 2007 in a reunion.
Answer: O' Cracker Where Art Thou?