Space to perform
Whether performing from your home, a studio or outside, consider what your audience is going to be looking at and whether it will be engaging. Performance venues may also offer spaces to stream from, even if they are not currently hosting live shows. Get in touch with some venues in your area and see if any are available.
At the very least, ensure your performance space has enough room to allow you to perform, and enough light for people to see you and what you’re doing. Most important, the space needs to have good internet.
Internet connection
There are two things that matter when it comes to your connection: speed and stability. Your internet connection should have an upload speed of at least 3Mbps to ensure high quality video and audio, and you should use an ethernet connection from your computer to your router where possible. If not, ensure that you are as close as possible to your router and using 5Ghz WiFi rather than 2.4Ghz if available. For the best chance of a stable WiFi connection, you should be able to see your router.
You can test the speed of your internet here. When testing, do so from the location you will be streaming from on the day of the show. A fast and stable connection should look something like this:
If the upload (purple) and download (green) lines are not relatively stable, you may experience buffering issues or disconnects. Something like this will probably result in a poor quality stream:
Audio
This is an important aspect of a live stream, particularly for musicians. If the audio is too quiet, muffled, distorted, or drops in and out, it can be frustrating for your audience. Depending on what music you play and how you perform, you may be able to get away with using the microphone on your phone. An intimate acoustic set might sound okay, but a doomcore megamix could end up sounding awful - even for fans of that sort of thing.
A dedicated microphone like the Blue Yeti has a number of configurable polar patterns for picking up the sound of an entire room. The Yeti is especially good if you’re a small acoustic ensemble, or one person with a single instrument. The only issue might be getting hold of one, given the increase in streaming.
For more complex setups - say a string quartet or a three piece freak-folk outfit with a vocalist - you may want to have a decent microphone on every instrument, the same way you would in a traditional live show. You can plug professional XLR mics and instruments into a standard mixer and then feed the stereo mix from that into your computer via an audio interface such as a Focusrite Scarlett 2i2. Or you can use a mixer with a built-in USB interface, such as the Mackie ProFXv3 or Yamaha AG06, which allows you to feed straight from the mixer into the streaming software on your computer.
Video
The camera is the most important piece of equipment for a live stream. Providing you have set up your performance space suitably (see above), a laptop or phone camera could give you a clear enough image for streaming. You can often connect your phone camera to your streaming software via your computer to use it as a webcam, or stream straight from your phone with software like Larix.
You also may have a DSLR camera which is capable of feeding a live signal into streaming software via a capture card, such as the Elgato Camlink. Just make sure your DSLR has the ability to output clean HDMI, like the Lumix GH5. If you want to get fancy, you can plug multiple cameras into your computer and control what is broadcast via your streaming software, e.g. by using scenes in OBS. Maybe now’s the time to attach a GoPro to your drummer’s forehead.
Computer
You need a fairly powerful computer to stream via OBS (or any other streaming software you choose). A Macbook Pro from the last two years running macOS 10.12 or newer should be capable, or a recent Windows PC with at least a 4-core Intel or AMD processor, a DirectX 10 capable graphics card and 4GB of RAM.
Lighting
The more light you can push through your camera’s lens, the better your stream will look. Even if you want to create a darker atmosphere, properly lighting yourself is important. Many streamers use a 3-point lighting setup to ensure they can be seen:
You can use lamps you already own to achieve this setup, or else there are some recommendations below. The key to good image quality is to ensure you are lit primarily by white light. You can experiment with more colorful lighting in the background. Time to get that lava lamp out!