Is it required to have license to sing an original song and to post in Social media?

No license is required to upload your song in social media. You can publish your cover song also. One of my friends is a very good musician. He uploads many of his performances in social media. He posts these programmes on youtube and facebook also. He will be placing them on WhatsApp also. He has not taken any licence.
You can go ahead and publish your song in any of the social media. You can post it on youtube by creating your own account there. You will get some revenue also if you get more views.

Covers are seen as your creation and not as the original artist's creation. It is so because you have added your own embellishments to the original song. Here are ways you could make your song/cover sound a bit different. If you are only going to sing over the original backing track, the musicians might still call it a copyright infringement. So alter the backing track by changing its tempo, changing the key or playing it on a different instrument. Or get hold of "karaoke" versions of the song from YouTube and credit the source in description. Usually karaoke versions are free to use. If you do not want all these headaches then just use karaoke apps. They have all rights of recently released songs. There you can freely express yourself in the way you like and share a link. There are many such apps in playstore and other store apps. But if doing just vocal cover wasn't your thing then go ahead and record all instruments. But always mention the original work in description with a notion of "Fair use".

Cover song means that the lyrics and music are not original. The song has been sung by others and it is known to people. So, it is not your original song. However, anyone can sing that song and upload it on social media sites. This does not require any license. However, it would be a good idea to mention that the particular song has been originally sung by XYZ.

There is no license required to sing an existing song in your voice and upload it in the internet sites or social media. Interesting thing is that you can very well use the original or your own music in the background. There is no restriction on that also.

The problem comes when a person says that he has composed that music or written that song which is in act a fraud and violation of copyright. One should refrain from such remarks or comments in public especially when one is successful in this line and becomes a big singer.

There are some sites in the internet like Smule, KaraokeParty, RedKaraoke, SingSnap, RisingStars and many others where you can register and become a member and then use the music soundtracks of the songs which are available there. With the help of a mike you can sing any song with its music and it will be stored in the site itself from where you can download it and send to your friends or audition or things like that.

You can pick up a duet song also and sing your part and leave it there. Someone will pick it up and sing the other part. You can sing like that with many other singers and even can chat with them online about the performance or how to further improve that. You can sing a song multiple times and keep the best one with you.

In my curiosity once I visited such a site and found that there are hundreds of registered members singing and practicing songs. Some of them have sung more than a thousand songs. For music lovers and budding singers it is a must try.

These are the best places to sharpen ones practice and talent in the field of music and singing. These sites are known as Karaoke sites also. Most of them are free and have a paid premium VIP section also.

There is no license for this activity. It is the most common activity around.

Now a days we have so many stage functions and other functions where the artists come and sing the old songs in their voice. This is so common and prevalent that even if some one tries to bring it under licensing it may not be feasible.

In most of the houses people have karaoke gadgets with them and people sing during the family or public functions at ease.

The sound tracks are used by the people left and right.

We could see hundreds of singers in a big cities and they are often invited in the functions organised by the locals to enjoy such songs. However, they are having sufficient atticates to pronounce the the name of original singer prior to sing such a song. Though the tone is melodius and very often the song resemble the tone of the original singer because of the consistent practice of the singe, even then it is not the original one despite the long appreciation of the audience.
These artists though get wide applause for their act still they lack the originality in their performance. Hence singing does not necessarily require license if they copy the tone of the original singers.

One doesn't require a licence for it. These days there are many apps too where one can record his or her voice on the music of the song and upload it on the social sites like Facebook. My kids have done this in the past. ". Star maker" is one such app where one can record his/her voice. The app rates the voice and gives rank to your song as per the points and that song you can upload on the social site.

Understand first that when you are planning to use any kind of existing thing for commercial gain then obviously original owners will claim and can sue you in court. Now for your problem , if you upload song for commercial gain then it can be blocked if owners wanted. Since now many fusion and remix are coming in market they have to pay some contributions to owners of song presently mostly are music companies.
For small scale publishing , does not matter more. So yes you can upload for your skills but do not market your posting for money gain.