Please note that this is a company listing not a brand listing, for the latter see: Brands & trademarks

MIDI/USB/wireless interfaces for classical string instruments
Keith McMillen Instruments (Violin, viola, cello & bass bow to wireless).

Classical string instrument accessories
Cavanaugh Company.

Classical string instrument stands
Athletic — Enrique Keller — Gewa Music — Gig Stands — König & Meyer — Hamilton Stands — KHS Group — Reliance International Corp. — Shar Products — Steinigke Showtechnic — Team International Co. — Ultimate Support Systems.

Violin/viola chin & shoulder rests
Cavanaugh Company — Dae-il — Finissima — Gatchell Violins Co. — Gewa Music — Guangzhou Pearl River Piano Group Co. — Izzo — JR Music Supply — Kun Shoulder Rest Inc. — Metropolitan Music Company — Michael Hammel — Parekh Exports — Shar Products — Shimro — Steinigke Showtechnic — Tempel — Viva La Musica — Wittner — Wolf.

Tailpieces, pegs, bridges, hangers and other classical string instrument hardware
Eric Meyer — Gewa Music — Grover-Trophy Music Company — GTRC Services — Guangzhou Pearl River Piano Group Co. — Izzo — JR Music Supply — Parekh Exports — Shimro — Strunal — Team International Co. — Tempel — Thomastik-Infeld — Wittner.

Bass & cello endpins and endpin sockets/holders
Cavanaugh Company — Grover-Trophy Music Company — Shimro — Viva La Musica — Wolf.

Classical string cleaning products
Bam — Barnes & Mullins — BG France — Blitz Inc. — Cavanaugh Company — Cory Care Products — Felix Bous — Generation Music — GTRC Services — Kolstein — Shar Products — Thunder Products.

Companies that have made classical string cleaning products in the past
Gerd H. Möller .

Classical string instrument mutes
Cavanaugh Company — Finissima — Gewa Music — Grover-Trophy Music Company — GTRC Services — Hosco — JR Music Supply — Metropolitan Music Company — Shar Products .

Companies that have made classical string instrument mutes in the past
.

Wolftone dampeners
Cavanaugh Company .

Rosin
Cavanaugh Company — Generation Music — Gewa Music — GTRC Services — Kafko International — Kolstein — Laubach — Nyman Harts (Bass only) — Pirastro — Savarez — Shar Products — Shimro — Team International Co. — Thomastik-Infeld — Thorvaldsson — Walter Geipel.

Classical string instrument cases and bags
Australis Music (Violin) — Bam — Barnes & Mullins — BG France — Cibeles Music — Concepta — David Gage String Instruments (DBass/Cello) — David Wexler & Co. — Enrique Keller — Fusion Products — Gatchell Violins Co. — Gator Cases — Gewa Music — Gig Ltd. — Guangzhou Pearl River Piano Group Co. — Hiscox cases — Jacob Winter — JR Music Supply — Kennith Loop International — Kolstein — Lang International — Lien Violins Instruments Ltd. — Luis Negri (Violin) — Mac Corporation — MTS Products — Musafia (Violins & violas) — Musicover — Pro Tec — Roder — Shanghai Chaobo Musical Instruments Co. — Shar Products — Shimro — SKB — Steinigke Showtechnic — Strunal — Team International Co. — Tiange Violin Co. — Unitec Products .

Companies that have made classical string instrument cases and bags in the past
Tribal Planet.

Classical strings educational materials
The Original Swab Co. .

Varnishes, glue and retouching supplies
Gewa Music.

Frogs
Shimro.

Classical string instrument tools
Grover-Trophy Music Company — Hosco — Metropolitan Music Company .

Bending irons
Gewa Music (Violin & gtr.) .