At this point in their career Saint Vitus had established themselves as a metal force to be reckoned with, creating three heavy metal classics and receiving praise from many in the music world, but still the metal world had largely left them unnoticed. Metal bands seemed only allowed to take a few paths - the dual-guitar, happy-go-lucky galloping style of Iron Maiden, the fast and Satanic sounds of Slayer, or the poppy and commercial "metal" produced by groups like Ratt and Motley Crue. A band like Saint Vitus fit in nowhere in the 80's metal scene with their slow and depressing riffs which took inspiration from groups like Black Sabbath and Pentagram, not Priest or Maiden or Metallica. With little to no commercial success at all, touring most often with other little-known (to the metal world) groups like Black Flag, Vitus could've easily sped up the pace and made some money, but instead of compromising their unique sound the group pressed on and got even heavier and even slower.
Mournful Cries doesn't really expand on any of the group's previous three albums, but what it does a perfect job of doing is creating an archetype for how nearly all doom metal bands to follow would sound. It takes the perfected formula established on their classic
Born Too Late album and simply makes it even doomier and even heavier. There's nothing flashy or bombastic about this music at all; it is stripped-down and raw doom metal that many headbangers at the time could not understand because it sounded so alien and barren, and were it not for the growing popular of doom metal over the past decade, it would sound just as alien and barren to listeners today. Luckily, groups like the Melvins and Electric Wizard took notice of what Vitus were doing and popularized it, bringing Saint's music to a far wider audience because of bands like those stating Vitus as an influence.
All tracks are slow, plodding, evil and heavy (except slightly uptempo opener "The Creeps") - many bands have tried to do an album like this since, but few, if any, doom bands since Vitus have been able to capture the doom sound so well. Vitus used their huge Sabbath influence to their advantage and still managed to sound unique, while many others have simply plagiarized in hopes of sounding as badass as their forefathers.