Here is a list of all the pieces in The Works project that are titled as some sort of a concerto but don't fit into any of the previous lists of solo (or small group) concerti. Many of them are concerti grossi, which is a special baroque form that made a small comeback in the 20th century. Two are concerti for unusual solo groups that didn't fit into any of the previous lists. The next group is a special genre of piece called “Concerto for Orchestra” that emerged in the 20th century. All pieces in this group are titled Concerto for Orchestra except the last one. There is a final list of miscellaneous pieces that don't quite fit into any of the other categories.
As with the other lists, each section is arranged roughly chronologically.
Concerto Grosso
Giuseppe Torelli: Op. 8 Nos. 1-12
G.F. Handel: Op. 3 Nos. 1-6; Op. 6 Nos. 1-12; "Alexander's Feast" Concerto
Antonio Vivaldi: Op. 3 Nos. 1, 2, 7, 10, 11
Arcangelo Corelli: Op. 6 Nos. 1-12
G.P. Telemann: TWV 54:D3
J.S. Bach: Brandenburg Concerti Nos. 1-6
Francesco Geminiani: Op. 2 Nos. 1-6; Op. 3 Nos. 1-6; Op. 7 Nos 1-6
Igor Stravinsky: Dumbarton Oaks Concerto
Bohuslav Martinu: Double Concerto for Two String Orchestras, Piano and TImpani
Alfred Schnittke: Concerto Grosso No. 1
Ellen Taaffe Zwilich: Concerto Grosso 1985
Concerti for Multiple Instruments
Ludwig van Beethoven: Triple Concerto (piano, violin, and cello)
Gunther Schuller: Concertino for Jazz Quartet and Orchestra
Concerto for Orchestra
Bela Bartok
Elliott Carter
Witold Lutoslawski
Roger Sessions
Michael Tippett
Joan Tower
Peter Maxwell Davies: Strathclyde Concerto No. 10
Pieces called “Concerto” that don't fit into any of the above categories
Giuseppe Torelli: 12 Concerti Musicali, Op. 6
Michael Tippett: Concerto for Double String Orchestra