2) Regarding the slow movement with the arpeggios in the solo part, we must notice that there is, actually, another similar example in Torelli's concerto production: the violin concerto A.2.3.6, published, posthumously, by Le Cène in Amsterdam in 1720 inside a collection of concertos by different Italian authors. Torelli's concerto is the fifth of this collection: “VI CONCERTI à 5 Stromenti (…) del Signo. F. M. Veracini, A. Vivaldi, G. M. Alberti, Salvini e G. Torelli”. A manuscript copy of this concerto is also held in the Archivio di San Petronio in Bologna. The second movement of this concerto is marked as “Largo e spiccato” and the solo part consists of broken chords presented in a figural motif.
Another similar case is represented, in a reduced setting, by the Sonata for violin and basso continuo in E minor A.1.3.8 / GieT60 (one manuscripted copy is held in the Archivio di San Petronio in Bologna, another one is held at the SLUB in Dresden, copied by Pisendel). The sixth movement of this sonata does not present any agogic indication but it presents a 'Largo and Spiccato' motif for the bass and arpeggios on the violin part.
Afterall the use of figural patterns in slow movements cannot be considered an exclusive prerogative of Venetian composers, nor a signature of them, since it can be found in compositions written by composers that were working at the Estense Court of Francesco II in Modena, to whom Torelli was very close (e.g., Sonata for violin and basso continuo op. 4 no. 6 and 8 by Tommaso Vitali).
3) It is true that in most of the compositions written by Torelli the harmonic rhythm is much slower. But this is easily explained by the fact that his education and his main activity as a composer were strictly connected to the church of San Petronio. That location forced Torelli and his colleagues to adapt their compositions to the specific characteristics of the space and its acoustic. Even if such a practice could have become a habit for a composer who was working daily in that space, a different approach in the harmonic mobility and rhythm for compositions that were not intended for San Petronio is still clearly visible.
4) A comparable rampant and prominent role for the soloist can be found in many works by Torelli, specially in those that have not been published during his life. It is understandable that a virtuoso player would have preferred to keep for himself the most difficult compositions in order to be able to bewitch his audience with 'special effects' while performing and also in order to publish those, less demanding, compositions that could have be more appealing for a larger number of people. The clearest example of exuberant violinistic language and full subjection of the orchestra in Torelli's production can be found in the violin concerto A.2.3.10. This is one of the concertos copied by Pisendel: the solos are technically more demanding – use of high positions, ascending lines to be performed on one string; the space given to the soloist is even larger – there is also a cadenza 'a capriccio' to be improvised in the last movement (since in the manuscript only the first bars of the cadenza are written out, leaving the rest of it to the fantasy of the performer).
5) The fact that this concerto presents two viola parts does not make it incompatible with Torelli. It is true that in all the works that he saw to the press during his lifetime he used only one viola part. While the publication of a collection of concertos with double viola part in the orchestra (e.g., Albinoni op. 5, Vivaldi op. 3) looks like a Venetian trend at the beginning of the XVIII century, it is well known that the double viola part was at that time still a common performance practice in Bologna, and the career of Torelli himself testifies to that, since he was hired in 1686 in the orchestra of San Petronio as a tenor viola player. Moreover, many of his compositions for San Petronio, now held in the Archivio of the church, contain double viola parts (e.g., Sonata for strings A.11.1.28/GieT 46, Concerto for two oboes and two trumpets A.9.1.6/GieT 31), equally easy to find also in the instrumentation used by Giovanni Paolo Colonna and Giacomo Antonio Perti.
Furthermore, there are few aspects in this Concerto that are not common to the Vivaldian way of writing. The opening exposition of the subject of the third movement (from bar 55 to bar 58) is entrusted only to the solo violin part without any accompaniment. I did not find any comparable case in Vivaldi's output of concertos, while it is a recurrent compositional technique used by Torelli. The sound of the solo trumpet that breaks the prayerful silence in the naves of San Petronio must have been a powerful experience, imprinted in the imagination of Torelli as a composer, who made large use of this tool. In several cases, and for different kinds of instrumentation, the exposition of the musical material is left to the soloist, alone, either for movements characterized by a fugato or imitative motif (e.g. in the Concerto for trumpet A.2.2.1/GieT 1, second movement; in the Concerto for 4 violins A.11.1.15/GieT 51, second movement; Concerto for 2 violins op. 8 no. 2 A.5.2.7/GieT 154, first and second movements) or simply as an expedient way to point out dynamic and timbre contrasts between one or two solo instruments and the tutti (e.g. Concerto for two trumpets A.5.1.2/GieT 15, first and fourth movements; Concerto for two trumpets A.5.1.5/GieT 19, first movement; Concerto for two violins op. 8 no. 1 A.5.2.1/GieT 153, first movement).
Another characteristic of the concerto in D minor is the lack of what Hutchings called “kinetic recurrence”, which is one of the major features of the Venetian school and particularly of Vivaldi (already from L'Estro Armonico op. 3). The themes used by Vivaldi for the external movements of his concertos are usually structured in rhythmic-melodic segments, so that when the theme is re-proposed during the same movement it can be presented in a fragmented way – sometimes almost as a stretto – in order to create the impression of a ritornello in the listener, but without the need of presenting again the thematic subject in its entirety: this is a very effective invention, that creates an increase of the compositional rhythm. However, this is a compositional tool that is not used amongst Bolognese composers and neither by Torelli, as far as I could observe.