1-2-3 had originally been billed as an integrated product with spreadsheet, database and word-processor functions, thus the name 1-2-3. In reality however, the product was a simple spreadsheet that allowed you to type in as much text as possible. In the 1980s truly integrated products, such as AppleWorks started to become popular, and so Lotus tried their hand.
Symphony was a DOS program that was loaded entirely into memory when started. Using the F10 key the user can switch between the various modes of the program, which include a spreadsheet very similar to 1-2-3, a word-processor that many described as a text editor, a communications program, simple database, and a graphics program. The program allowed you to split the screen and view any of these "modules" running at the same time. It was at this point that the user would notice that changes made in one module were reflected in others in real-time, perhaps the package's most interesting feature.
Most integrated packages at the time tended to be very simple. This was true for Symphony as well, with the exception of the spreadsheet. In that respect Symphony can be considered "1-2-3 and some utilities", which has to be expected given the 640k limit the program ran in. Thus it's perhaps not surprising that the program, while somewhat popular, never managed to gather a truly large user base.