Wolf instruments: the model in G or quint-bassoon is marketed more toward children as its slightly smaller size suits them better, while the F or quart-bassoon is more suited to older children or professionals due to its slightly bigger size as well as its feeling and sounding more like a full-sized bassoon, although in its basic children's model it has limited professional use due to the lack of full modern keywork and indeed some professional players using this instrument have opted to have alternative F and G keys added to Wolf's professional instrument (standard features on the regular bassoon) to facilitate the playing of more advanced music. Octave bassoon Instruments pitched an octave above the bassoon are, like all smaller bassoons, historically quite old instruments. Virtually no literature exists for this size of bassoon other than a partita by Frost (or Trost?) and a cantata by Zachau (which specifies "Bassonetti" which would appear to be small bassoons). The instrument has enjoyed something of a revival in the past decade. Once again both historically accurate copies and modern instruments are being constructed. The modern instruments are very simple in their fingering, needing only four keys (although as many of nine or more can be had), considerably fewer keys than the original bassoon. The instrument is not, however, fully chromatic. It lacks the bottom B and C, which is akin to Baroque and Classical instruments. This instrument is not a remedy for high notes on the bassoon nor can it extend the range considerably. The octave bassoon can generally only reach the written F above the bass clef (but sounding an octave higher) although professionals may be able to extend this range. The sound is thin and would not be out of place in a Renaissance or Baroque wind ensemble. Due to the somewhat smaller size and abundance of cross-fingerings, technique on the octave bassoon may be somewhat challenging for a non-professional. Octave bassoons (alto bassoons) have been made in various keys, D, D (an octave above the lowest and largest tenoroon), and C. Tenor bassoons The tenor bassoon is a historically very old instrument evolved from the tenor dulcian or curtal. There is virtually no literature for the instrument aside from a few pieces written in the late Baroque by relatively obscure composers (namely a work by Frost). An old theory that the exposed English horn part in Rossini's overture to