...this doesn't seem like it is at all worth giving up 1% of battery life. I don't think it's even worth giving away 0.25% of battery life to detect whatever the 70k songs stored in the database is, nor is it worth the space the database is taking up on the device. The question of "what song is this" comes up maybe once a month at best, and apps like Shazam already exist and have much deeper databases to search throu…
I would argue that it's not worth my 30 seconds to unlock my phone and open Shazam (which btw turns on the display and the radio, which then triggers other apps to poll for notifications, so there goes your 1%) I would also bet the database is probably not much bigger then the shazam app itself. I frankly just find it a well balanced solution both in terms of UX and in terms of engineering.
I don't know what you're trying to say here. Shazam has millions of songs in their database, according to the original paper the offline mobile recognition system by google just has something over 70k finger prints. That's the big benefit of using an online system, you don't have to have all the fingerprints stored locally and also don't have to stick to the low power constraint.