When you sync music to your iPhone, iPad or iPod, you can choose to manually manage this content. Instead of having iTunes sync all of your library, or specific playlists, you can choose to pick each song, album or playlist you want to add to your device. To do this, you check an option from the Summary tab when the device is connected:
Manually managing music can be a headache. You have to find each item you want to copy to the device, then drag it. But iTunes 12 has an improved interface for this process. Here’s how to add music to an iOS device manually.
First, select the iOS device in iTunes. Scroll down to the On My Device section; you’ll see the various types of content. Click Music, and you’ll see this.
Next, click Add To. You’ll see a column at the right of the window, showing whats on the device, and, to the left, My Music is selected.
You can select items from the My Music list and drag them to the right-hand column. I have the Column Browser displayed in the above screenshot; you can do this by pressing Command-B. It makes it easier to find items by genre, artist, etc.
To add playlists to your device, click Playlists in the header bar; you’ll see the playlists in a sidebar to the left.
Just click a playlist to select it, then drag it to the list at the right of the window. Continue until you’ve added everything you want, then click Done, and iTunes will copy your music to your iOS device.