To compare Rihanna to Madonna is like comparing NSync to the Beatles; with Madonna it isnt just about number 1's or charts, its about cultural impact and legacy. Everything Rihanna is doing today is largely thanks to Madonna's efforts when she first stepped out of the cab in Times Square, with just $50 to her name and a heart full of dreams. The rest is just musical legend. Back in 1980 there were no strong female icons on the level of today, okay we had Debbie Harry but she was too coked up to even give a crap, Madonna through her dealings with sexism in the industry fought long and hard to establish herself as a credible force, a force to be taken seriously and equal to all men. Some still try to demean her success now. And thats where she and Rihanna differ. Rihanna may be using Madonna's bluprint, but she is sadly moulded and essentially marketed by music execs to generate money for them, shes getting rich but at the expense of her artistic freedom and integrity! Madonna's body of work has been as much a vehicle for her thoughts as it has her preference, she has channelled gospel, jazz, folk, pop, rock, R&B, swing, country, EDM, far eastern and beyond. Shecwas credited in 1995 for bringing Electronica to the masses and working with obscure producers only added to her credibility! Its not just genres either, Madonna has touched on social commentary where most artists wouldnt even venture! 4 of her videos have been banned due to cultural clashes over content, she has been stopped from performing in Italy, Russia and Ukraine due to problems with show content. She has riled the catholic church, promoted homosexuality and been an advocate for womens lib for decades... Even her fashion choices can be seen decades down the line and invite social discussion like no other! The Virgin wedding dress, the conical Gaultier bustiere, the D&G cowgirl get up, the Versace kimono's... Her fashion stays in your mind and the publics eye!

As for achievements, to see Madonna's true worth you just have to look at her tours, she is the only artists who can take a world tour to any city, any country on any continent and fill out stadiums! Her chart legacy in hundreds of countries is unsurpassed! In Europe she is by far the biggest selling female, in the UK 1 of her albums has sold 3.9 million alone, 4 others over a million! Austrlia, Japan, France she is their biggest selling female and it just goes on! As it stands Madonna was just notched up 310 million album sales and according to Guinness World Records 2014 she has surpassed 265 million in singles, when she releases ALL her singles digitally with ALL original edits and mixes, this will double (only singles since Hung Up have her singles been digitally available) her first decade alone generated more than a billion in revenue for then parent company Warners.
So you see, Rihanna may be inching closer to Madonna's chart achievements on certain charts, but she is nowhere near achieving all that Madonna has culturally, and that is why the public refer to her as a Queen. Who else could release a major album containing a scathing attack on American culture, yet remain able to sell despite a blanket airplay ban?! Who else could place a soft porn book at the top of the global best sellers list or have 3 tours in the top 10 grossing of all time? I'll tell you... Madonna, thats who!