• Piano is a "wildcard"; it doesn't affect the type of group. For example, a string quartet with added piano counts as CS, while a woodwind quintet with added piano counts as CW. A group consisting of only pianos is CP.
• In a vocal piece, guitars and drums are considered a wildcard (like a piano). For example, a piece for choir, piano, guitar, and drums counts as a vocal piece.
• French horns count as either woodwind or brass.
• If the music suggests that it could be played by multiple instrument groups (for example, a Baroque "sonata for violin or flute"), it is placed in the Mixed category (CM or LM). If you can't find a piece in its normal category, try looking in CM or LM!
• "Chamber music" means "any ensemble that isn't large" -- solo pieces are considered chamber music for one musician. There is one exception: in the vocal category, CV is also used for choral pieces of which we only have one copy.

Vocal pieces (CV, LV, and MV) have not been rated by difficulty.

• In some cases the piano part doesn't count towards this number. For example, many baroque pieces for large string ensemble includes a piano part which simply doubles all the string parts. In such cases, the piano part isn't included in the number of parts. The same is true of vocal pieces -- if the piano part simply doubles the vocal parts, it isn't included towards this number.
• Some albums and collections contain pieces for multiple sizes of groups (solo, duets, trios). In such cases, I list the average size of group.
• Some pieces contain optional parts. Such parts do not count towards this number.

• If there is more than one musical part for a specific instrument, the instrument name is followed by roman numerals denoting which part is is -- for example, "VN I, VN II".
• If there is more than one copy of a part, then the instrument name is followed by a "-x", where x is the number of parts. For example, "VC-3" means that there are three cello parts, while "VN II-4" means that there are four second violin parts.
• If two instruments share the same part, they are linked with an ampersand "&". For example, "FL I&FL II-2" means that there are two copies of a part which contains both first and second flute parts.
• If there is a choice about instruments, they are denoted with a slash "/". For example, "VN III/VA" means that the part can be played with either a third violin or a viola, while "VC/BSN" means that it can be played by cello or bassoon.
• In vocal ensembles (CV, LV, and MV), vocal ranges are abbreviated as SATBMR. In other types of ensembles (mostly CM and LM), they are abbreviated as VOCS, VOCA, etc.

In technical terms, you are searching for a specific text string within the instrument fields of the catalogue entires. In practical terms, this means that you can search for things like:

• VN II
• CL IV
• FL I&FL II
• VA, VC
• SATB
• TTBB