Music scholars have concluded that The Beatles were greater than the sum of their parts. Unfortunately, last night's Spontaneous Combustion Orchestra proved that the parts were greater than the whole. One musician seated nearby commented, "It's trolling for moments." As a presentation argument for spontaneously improvising chamber orchestras, the concept has encumbrances. And as the experiment unfolded, that became starkly apparent. On the Neptune Studio Theatre stage, each of the previous (and largely successful) Spontaneous Combustion units: guitars, strings and reed instruments with percussion, were positioned at ominous distances, orphaning them. Whereas the small groups thrived, thanks to close proximity for ear and eye contact in the more intimate venue of 1313 Holis Street, the yawning gulfs distancing the three units nixed such easy and instant rapport. Indeed, several times last night, reed players wandered like lost souls about the stage seeking out someone or others outside of their own group with which to interact, with yearned-for immediacy. Another telling moment occurred when guitarist Gordon Grdina, during an energetic workout of hares and hounds note playing from the reeds, abruptly took to furiously downstroking his guitar strings like rifle shots. When nothing accrued from his intervention, Grdina simply ceased playing. And slumped over his instrument. There were, happy to report, moments of delightful musicality from the entire ensemble. Musicians of this calibre deliver. But I'm not certain, however well-intentioned that, when it comes to in-the-moment improvisation, such scale is viable. My conclusion? It was well worth the try. Kudos to artistic director Lulu Healy and Jerry Granelli for their courage. But, based on the two successful preliminary Spontaneous Combustion sessions I caught at 1313 Hollis Street, I'd say: small is good; big, not-so-much.