The organ of the church of San Filippo Neri is a fine example of the Lombard organ school of the nineteenth century. It was built in 1816 by Giuseppe II Serassi, the most important member of a family of craftsmen builders founded in the first half of the eighteenth century by Giuseppe Serassi "the old" and active until the end of the nineteenth century. In this period the organ was used with increasing success in the execution of transcriptions of symphonies and opera arias Bel Canto, as well as original compositions in the same style. The Serassi worked to get the instrument maximum tonal variety and effects bands, while maintaining a solid foundation of organ registers typically coming from the tradition of Renaissance and Baroque.
They repeated almost never the same phonic setting in over eight hundred organs scattered throughout Italy but specifically characterized each of them with elegance searching for most varied effects. The most common model is still the one to one keyboard as in the case of the organ of the church of San Filippo Neri.
The keyboard, with short octave, consists of 50 keys and range C1-E5 and division Bassi-Soprani at B2-C3. The pedal, with range C1-G#2, is made of 17 pedals, with short octave, lectern-like with 12 real notes. The registers are driven by levers placed in two columns to the right of the keyboard with the following setting:
|First column||Second column||Accessories||Decoy pedals|
|at the right of the keyboard||at the right of the keyboard||over the pedalboard|
|Cornetto I soprani||Principale bassi||Combinazione libera alla lombarda||Trombe soprane|
|Cornetto II soprani||Principale soprani||Tirapieno||Corno inglese soprani|
|Trombe basse||Principale II bassi||Terza mano||Corni dolci soprani|
|Trombe soprane||Principale II soprani||Uccelliera||Ottavino soprani|
|Corno inglese soprani||Ottava bassi||Rollante|
|Viola bassi||Ottava soprani|
|Corni di tuba dolce soprani||Duodecima|
|Flauto traversiere soprani||Decimaquinta|
|Flauto in duodecima soprani||Decimanona|
|Flauto in ottava bassi||Vigesimaseconda|
|Flauto in ottava soprani||Ripieno 4 file|
|Ottavino bassi||Contrabbassi con ottave|
|Voce umana soprani||Tromboni al pedale|
|Principale bassi (Aziona la prima ottava del pedale)|
The instrument was restored in 1995 by the Bottega Organara Dell'Orto & Lanzini.