Trio

A trio is a group of three things, or a group of three persons who are doing something together.

In music

Trio (music), three people performing music together
Piano trio (piano, violin, cello)
String trio (violin, viola, cello)
Trio (jazz) (piano, double bass, drums)
Power trio (electric guitar, bass guitar, drum kit)
The middle section of a piece which is usually a minuet and trio or scherzo and trio
The third section of a march (music)
Trio (band), a German pop band who wrote "Da da da"
The Trio, one incarnation of Trey Anastasio (band)
Trio (album), a 1987 recording by Dolly Parton, Emmylou Harris and Linda Ronstadt. The group is also sometimes referred to as Trio.
Trio 2 (album), a 1998 recording by Dolly Parton, Emmylou Harris and Linda Ronstadt
The Trio, a live 1961 album featuring a jazz trio led by the Canadian jazz pianist Oscar Peterson

In other entertainment:
Trio (TV network), a former American cable and satellite television channel owned by NBC Universal
Trio (novel), a 1943 novel by Dorothy Baker
Trio (1950 film), a movie directed by Ken Annakin
Trio (TV series), a South Korean television drama produced by the MBC in 2002
Trio (Stargate Atlantis), an episode of the television series Stargate Atlantis

Other uses:
Trio, a speaker phone, personal handset and voice recorder made by Ipevo
Trio AB, a Swedish telecommunications company
Trio, South Carolina 
The European trade name of Japanese concern Kenwood Electronics
An Australian company producing durable DVD Players
A United Kingdom chocolate bar of the 1980s
The S3 Trio 3D Graphics Accelerator.
The Trio or Tiriyó people of South America, or the Tiriyó language
TRIO, a US government outreach program for disadvantaged students
An abstract family of languages with particular closure properties

 Related pages 
3 (number)
Triplet (disambiguation)
Triad (disambiguation)
Triumvirate
List of fictional trios