Teachers Pay Teachers is a platform where educators can support each other and share resources. There are all kinds of resources available from composer studies, music theory, games, and centers.
This lesson plan database developed by NAfME and its members has a large resource of lesson plans. You must be a NAfME member in order to access and contribute to this lesson plan database.
This YouTube channel has many song tutorials for the ukulele. I often use this as a resource when my students have their own ukulele and want to learn on their own time. This resource is great for elementary all the up to adult ukulele learners!
The blog has a myriad of resources for the elementary music classroom. I have followed this blog for years and have pulled resources and ideas from it quite often. Examples of resources I have used recently are music centers and music technology/iPad apps.
This website has animated videos of songs, many with karaoke style lyrics to help reinforce early literacy. These resources are especially great for prek or kindergarten classes.
This website has a large database of public domain sheet music that is on a beginner student level. This website is a great resource for pulling repertoire for beginner students.
This website has a wide variety of resources such as sheet music, lesson plans, composer biographies written with elementary level vocabulary, music theory worksheets, and much more. This website is geared toward elementary music but could also be useful in some middle school applications.
This website has themed worksheet resources for music theory. These worksheets are geared toward elementary students. There are free resources available, but a subscription to the site will provide complete access to their entire catalog of worksheets.