How accurate are the sites that tell you BMP of songs? ..for sake of discussion, let's take the song Can't Find My Way Home.  When I listen to You Tube videos/ covers, and mimic the tempo on my acoustic for recording: a matching drum pattern that sounds good, gets in the ballpark of 140 ! Ok, if you look up the BMP it says 84! Huh. K have heard slower versions, but thats slow! I need a better way, and i am not that skilled to just tap and calculate. Thanks

You can drag the Audio into Sonar, then drag it t the time line and it will create a tempo map. Then if the BPM fluctuates it will track this.
 
I've done this with a number of songs I am practicing bass too sometimes added a metronome or straight kick if I am struggling with the timing of my phrasing.  I have found they sync well, so the extraction has been accurate.

Are you referring to the audio from a you tube video? 

Any audio, but yes I used audio from Youtube videos
 
I want you back - Jackson 5
Animal Spirits - Vulfpeck
Ain't no Mountain High enough - Tammy and Marvin
 
were my recent extractions

I know any audio file can be dragged in to Sonar but forgive my naive question..how do you extract the audio fro a You Tube video?

You can get add-ons to your browser. I use Firefox with
https://addons.mozilla.org/en-US/firefox/addon/1-click-youtube-video-downl/?src=userprofile
 
It will download the video, but Sonar will just take the audio when you add to the track

Ok good info. Thanks loads...in mean time found some apps do to that on Android

It's worth knowing that "unofficial" music video uploads on YouTube have often been sped up or slowed down by the uploader in order to fool the music recognition algorithm and avoid copyright takedown notices. I often come across songs there which are significantly faster or slower than the original.