Question: Which underground rock band was formed first: electronica group Liars or alternative rock trio The Jon Spencer Blues Explosion?

Context paragraphs:
Brassy (band): Brassy were an English rock/hip hop band, formed in 1994 in Manchester by American singer Muffin Spencer, younger sister of Jon Spencer (of Jon Spencer Blues Explosion).  The band split up in 2003 after releasing 2 studio albums.

Jon Spencer Blues Explosion: The Jon Spencer Blues Explosion is an American alternative rock trio, formed in 1991 and based in New York City, New York.  The band consists of Judah Bauer on guitar, backing vocals, harmonica and occasional lead vocals, Russell Simins on drums and Jon Spencer on vocals, guitar and theremin.  Their musical style is largely rooted in rock and roll although it draws influences from punk, blues, garage, rockabilly, soul, noise rock, rhythm and blues and hip hop.  They have released nine official studio albums, collaborative records with Dub Narcotic Sound System and R.L. Burnside as well as numerous live, singles, out-take albums, compilations, remix albums and, in 2010, a series of expanded reissues.

Plastic Fang: Plastic Fang is the seventh official release by the American punk blues group The Jon Spencer Blues Explosion, released on Matador in 2002.  "She Said" was released as a single and a music video was filmed for it.  In the video, Jon Spencer is a vampire being hunted by nuns whom he eventually seduces into a striptease en masse, before fighting and dying at the hands of a vampiress.

Now I Got Worry: Now I Got Worry is a 1996 studio album by the American punk blues band The Jon Spencer Blues Explosion.  The album opens up with Spencer screaming.  "Fuck Shit Up" is a cover of a Dub Narcotic song.  The man depicted on the cover is Jon Spencer.  "Wail" became a brief hit for the band and its music video was directed by "Weird Al" Yankovic.

Jon Spencer: Jon Spencer (born 1965) is an American singer, composer and guitarist.  He has been involved in multiple musical acts, such as Pussy Galore, Boss Hog, Heavy Trash and The Jon Spencer Blues Explosion.

Damage (Blues Explosion album): Damage is the eighth studio album by American punk blues band Blues Explosion, released in 2004.  This is the first album that the band has released under the abbreviated name "Blues Explosion" rather than their previous name, "The Jon Spencer Blues Explosion".  Spencer said about the band name change:

Liars (band): Liars is an Australian-American rock band formed in 2000.  Angus Andrew is the founding and only constant member of Liars.  Previous members include Aaron Hemphill who played with the band from its inception until his amicable departure from the project in 2017, and Julian Gross who joined the band for their second album, "They Were Wrong, So We Drowned" released in 2004, and played with the band until his departure in 2014.  Liars have released eight studio albums and are signed to Mute Records.  They combine elements of punk-rock with electronica.

Butter 08: Butter 08 was a short-lived musical side-project whose members consisted of Yuka Honda and Miho Hatori of Cibo Matto, Russell Simins of the Jon Spencer Blues Explosion, Rick Lee of Skeleton Key and director Mike Mills.  The band released just one album, the self-titled "Butter 08" in 1996 on Beastie Boys' now defunct Grand Royal record label.  The album features guest performances by future Cibo Matto members Timo Ellis and Sean Lennon as well as a performance by filmmaker Evan Bernard who directed music videos for several Grand Royal artists as well as for Cibo Matto and the Jon Spencer Blues Explosion.

Heavy Trash: Heavy Trash is an American rockabilly band based in New York City, formed by Jon Spencer of The Jon Spencer Blues Explosion and Matt Verta-Ray (formerly of New York bands Madder Rose and Speedball Baby).  The band's music draws from an eclectic mix of genres, including rock & roll, rockabilly, blues, alternative country, and garage rock or garage punk.  They are currently signed to Yep Roc Records, Bronzerat Records and Crunchy Frog Records.

A Reverse Willie Horton: A Reverse Willie Horton is either the debut album, or an early bootleg album, by the New York City-based Jon Spencer Blues Explosion.  Few (500) copies of the album were produced; however, some songs are featured on the group's next two albums, 1992's The Jon Spencer Blues Explosion and 1993's Crypt Style, albeit in a different mix or recording altogether.  However, sound of the recording is closer to the Crypt Style LP.  All three albums are made up of tracks recorded in 1991 by producer/engineer Kramer and Steve Albini (in separate sessions).

Supporting paragraphs: Liars (band) Jon Spencer Blues Explosion
Answer: Jon Spencer Blues Explosion