Uploading an MP3 From an External Source to Tumblrby Nick Peers
You can share your own music, as well as music from your friends and favorite bands, on your Tumblr blog. When you create a new audio blog post, you can search for an MP3 on Tumblr or upload it from your computer. You can also use an external source, such as YouTube or SoundCloud. Tumblr is able to extract the audio from the external source and post it on your blog. To listen to the MP3, your readers just need to click the "Play" button.
Uploading From Tumblr or Your Computer
Click the "Audio" icon after you log in to your Tumblr account to start a new audio post. Type the name of the MP3 into the "Search" field. If the MP3 is already on Tumblr, select it from the list of suggestions. If you can't find it, click the "Upload" tab, click "Choose File" and then upload the MP3 from your hard disk. Type a description for the MP3, check the "I have permission to let Tumblr" box and click "Post" to post the MP3 on your blog. You can upload a single MP3 from your computer per day; the MP3 must not be larger than 10MB.
Uploading From an External Website
Navigate to the page that contains the track you want to post on Tumblr and copy its URL to the clipboard. On Tumblr, click the "Audio" icon and then click the "External URL" tab. Paste the URL from the clipboard into the URL field. Type or paste a description for the audio track into the "Description" box and then click "Post" to post the track on your Tumblr blog. The description is optional. Note that Tumblr does not support HTTPS URLs or URLs to pages that require authentication.