Please give a summary of the type of recordings Spalding made by year.

Context: During the 78 era, when the maximum capacity of a single ordinary record side or cylinder was less than five minutes, Spalding recorded extensively for Edison Records, with some issues on cylinders and many more on diamond discs. Most featured short works or encore pieces that could fit on a single record side. These recordings were all by the acoustical process, as well as vertically-cut, through 1925, but he made his first electrical recordings in 1926 for Brunswick Records using that company's problematic "Light-Ray" system. After his unsatisfactory experience with Brunswick, Spalding went back to Edison and made some electrical Edison hill-and-dale Diamond Discs as well as a very few Edison "Needle Cut" lateral recordings in late 1928. These were much better recorded than Spalding's Brunswicks, but the Diamond Discs sold as scantily as the rest of Edison's product in that period, and the "Needle-Cut" discs were issued only for a very short time—from August to November 1929—and are exceedingly rare today. Following the Edison company's demise in November 1929, he recorded a handful of more extended works broken across multiple sides for RCA Victor Records.

Answer: 1925: Vertically-cut acoustic recordings
1926: First electrical recordings for Brunswick Records
1928: Electrical recordings using Edison hill-and-dale Diamond Discs and "Needle Cut" recordings.